Cleaning systems for additive manufacturing apparatuses and methods for using the same

ABSTRACT

Embodiments of the present disclosure are directed to additive manufacturing apparatuses, cleaning stations incorporated therein, and methods of cleaning using the cleaning stations.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Patent ApplicationNo. 63/107,163, filed Oct. 29, 2020, for “Cleaning Systems For AdditiveManufacturing Apparatuses And Methods For Using The Same,” which ishereby incorporated by reference in its entirety including the drawings.

TECHNICAL BACKGROUND

The present specification generally relates to additive manufacturingapparatuses and, more specifically, to cleaning systems for additivemanufacturing apparatuses and methods for using the same.

Additive manufacturing apparatuses may be utilized to “build” an objectfrom build material, such as organic or inorganic powders, in alayer-wise manner. Early iterations of additive manufacturingapparatuses were used for prototyping three-dimensional (3D) parts.However, as additive manufacturing technology has improved, there is anincreased interest in utilizing additive manufacturing apparatuses forlarge-scale commercial production of parts. One issue of scalingadditive manufacturing apparatuses to commercial production is improvingthe through-put of additive manufacturing apparatuses to meet commercialdemands.

Accordingly, a need exists for alternative additive manufacturingapparatuses and components thereof which improve manufacturingthrough-put.

SUMMARY

In a first aspect A1, a cleaning station comprises: a first wipe memberrotatable about a first rotational axis comprising one or more wiperblades; a first wipe reservoir containing a volume of cleaning fluidtherein, the first wipe reservoir located adjacent to the first wipemember such that as the first wipe member is rotated about the firstrotational axis, the one or more wiper blades are rotated into and outof the volume of cleaning fluid in the first wipe reservoir; a secondwipe member rotatable about a second rotational axis parallel to thefirst rotational axis, the second wipe member comprising one or morewiper blades; a second wipe reservoir containing a volume of cleaningfluid therein, the second wipe reservoir located adjacent to the secondwipe member such that as the second wipe member is rotated about thesecond rotational axis, the one or more wiper blades are rotated intoand out of the volume of cleaning fluid in the second wipe reservoir;and a wet cleaning member comprising a fluid channel containing a volumeof cleaning fluid therein, wherein the wet cleaning member is positionedbetween the first wipe member and the second wipe member along alongitudinal axis extending substantially perpendicular to the firstrotatable axis and the second rotatable axis.

In a second aspect A2, a cleaning station comprises the cleaning stationof aspect A1, further comprising a spit capture tray containing a volumeof cleaning fluid therein.

In a third aspect A3, a cleaning station comprises the cleaning stationof aspect A2, wherein the spit capture tray comprises a first side walland a second side wall, and wherein a height of the first side wall isless than an height of the second side wall.

In a fourth aspect A4, a cleaning station comprises the cleaning stationof any of aspects A1-A3, further comprising a cover operable to createor maintain a non-curing environment around a print head.

In a fifth aspect A5, a cleaning station comprises the cleaning stationof any of aspects A1-A4, further comprising: a cleaning station vesselpositioned below the first wipe member, the second wipe member, and thewet cleaning member to receive cleaning fluid therefrom.

In a sixth aspect A6, a cleaning station comprises the cleaning stationof aspect A5, wherein the cleaning station vessel comprises a bottomsurface that is angled with respect to a horizontal plane and withrespect to a vertical plane.

In a seventh aspect A7, a cleaning station comprises the cleaningstation of any of aspects A5-A6, the cleaning station vessel comprisinga main cleaning vessel drain positioned at a lowest vertical point ofthe cleaning station vessel.

In an eighth aspect A8, a cleaning station comprises the cleaningstation of any of aspects A5-A7, further comprising an overflow vesselat least partially surrounding the cleaning station vessel.

In a ninth aspect A9, a cleaning station comprises the cleaning stationof any of aspects A1-A8, wherein at least one of the first wipereservoir and the second wipe reservoir comprise a brush or a wiperblade positioned therein to mechanically clean the corresponding firstor second wipe member.

In a tenth aspect A10, a cleaning station comprises the cleaning stationof any of aspects A1-A9, further comprising: a first motor coupled tothe first wipe member to cause the first wipe member to rotate about thefirst rotational axis; and a second motor coupled to the second wipemember to cause the second wipe member to rotate about the secondrotational axis.

In an eleventh aspect A11, a cleaning station comprises the cleaningstation of any of aspects A1-A9, further comprising: a motor coupled tothe first wipe member and the second wipe member to cause the first wipemember to rotate about the first rotational axis and to cause the secondwipe member to rotate about the second rotational axis.

In a twelfth aspect A12, a cleaning station comprises the cleaningstation of any of aspects A1-A11, wherein the wet cleaning member isstationary with respect to the first wipe member and the second wipemember.

In a thirteenth aspect A13, a cleaning station comprises the cleaningstation of any of aspects A1-A12, further comprising a purge bin,wherein the first wipe member rotates in a direction effective to directmaterial from the one or more wiper blades of the first wipe member intothe purge bin.

In a fourteenth aspect A14, a cleaning station comprises the cleaningstation of aspect A13, further comprising a wiper blade cleaning memberbetween the purge bin and the first wipe reservoir.

In a fifteenth aspect A15, a method of cleaning a print head comprises:rotating a first wipe member and a second wipe member into a contactposition in which one or more wiper blades extends upwards verticallyfrom each of the first wipe member and the second wipe member; flowingcleaning fluid to a cleaning member positioned between the first wipemember and the second wipe member; passing the print head over the firstwipe member, thereby enabling the first wipe member to removecontaminants from the print head; passing the print head over thecleaning member and the second wipe member, thereby enabling the secondwipe member to remove cleaning fluid from the print head; and rotatingthe first wipe member and the second wipe member into non-contactposition in which one or more wiper blades are not extending from thefirst wipe member or the second wipe member in a substantially verticaldirection.

In a sixteenth aspect A16, a method comprises the method of aspect A15,further comprising: applying backpressure to the print head prior topassing the print head over the first wipe member.

In a seventeenth aspect A17, a method comprises the method of any ofaspects A15-A16, further comprising: passing the print head over a spitcapture tray adjacent to the second cleaning member; and applyingbackpressure to the print head during passing of the print head overspit capture tray, thereby equilibrating the print head for printing.

In an eighteenth aspect A18, a method comprises the method of any ofaspects A15-A17, further comprising: providing a flow of cleaning fluidto the spit capture tray.

In a nineteenth aspect A19, a method comprises the method of any ofaspects A15-A18, further comprising: rotating the first wipe member andthe second wipe member to contact the one or more wiper blades withcleaning fluid contained in a wipe reservoir positioned below the firstwipe member and the second wipe member.

In a twentieth aspect A20, a method comprises the method of aspect A19,further comprising: collecting cleaning fluid from the wipe reservoirand the cleaning member in a cleaning station vessel.

In a twenty-first aspect A21, a method comprises the method of aspectA20, further comprising: continuously removing the cleaning fluid fromthe cleaning station vessel.

In a twenty-second aspect A22, a method comprises the method of any ofaspects A15-A21, wherein the print head comprises a deflector plate thatmaintains contact between the print head and the one or more wiperblades of the second wipe member.

Additional features and advantages of the additive manufacturingapparatuses described herein, and the components thereof, will be setforth in the detailed description which follows, and in part will bereadily apparent to those skilled in the art from that description orrecognized by practicing the embodiments described herein, including thedetailed description which follows, the claims, as well as the appendeddrawings.

It is to be understood that both the foregoing general description andthe following detailed description describe various embodiments and areintended to provide an overview or framework for understanding thenature and character of the claimed subject matter. The accompanyingdrawings are included to provide a further understanding of the variousembodiments, and are incorporated into and constitute a part of thisspecification. The drawings illustrate the various embodiments describedherein, and together with the description serve to explain theprinciples and operations of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically depicts components of an additive manufacturingapparatus according to one or more embodiments shown and describedherein;

FIG. 2A schematically depicts an embodiment of an actuator assembly foran additive manufacturing apparatus according to one or more embodimentsshown and described herein;

FIG. 2B schematically depicts a cross section of the actuator assemblyof FIG. 2A;

FIG. 2C schematically depicts a cross section of the actuator assemblyof FIG. 2A;

FIG. 3 schematically depicts a portion of control system for an additivemanufacturing apparatus according to one or more embodiments shown anddescribed herein;

FIG. 4A is a perspective top view of a cleaning station of an additivemanufacturing apparatus according to one or more embodiments shown anddescribed herein;

FIG. 4B is a side cross-sectional view of the cleaning station of FIG.4A;

FIG. 4C is an opposite side cross-sectional view of the cleaning stationof FIG. 4A;

FIG. 4D is a front cross-sectional view of the cleaning station of FIG.4A;

FIG. 5 is a side cross-sectional view of a cleaning station of anadditive manufacturing apparatus according to one or more embodimentsshown and described herein;

FIG. 6A schematically depicts an example embodiment for cleaning a wipemember using wiper blades fixed within a wipe reservoir according to oneor more embodiments shown and described herein;

FIG. 6B schematically depicts an example embodiment for cleaning a wipemember using rotating brushes according to one or more embodiments shownand described herein;

FIG. 6C schematically depicts an example embodiment for cleaning a wipemember using a wipe reservoir according to one or more embodiments shownand described herein;

FIG. 6D schematically depicts an example embodiment for cleaning a wipemember using a fixed brush according to one or more embodiments shownand described herein;

FIG. 6E schematically depicts an example embodiment for cleaning a wipemember using a sprayer according to one or more embodiments shown anddescribed herein;

FIG. 6F schematically depicts an example embodiment for cleaning a wipemember using a wipe reservoir containing cleaning fluid according to oneor more embodiments shown and described herein;

FIG. 6G schematically depicts an example embodiment for cleaning a wipemember using an adjacent rotating cleaning member according to one ormore embodiments shown and described herein;

FIG. 6H schematically depicts an example embodiment for cleaning a wipemember using motion of the wipe member according to one or moreembodiments shown and described herein;

FIG. 7A is a schematic perspective view of a wet cleaning memberincluding two blades in a wet wipe cleaning section of an additivemanufacturing apparatus according to one or more embodiments shown anddescribed herein;

FIG. 7B is a cross-sectional front view of a wet cleaning member in awet cleaning section of an additive manufacturing apparatus according toone or more embodiments shown and described herein;

FIG. 7C is a schematic perspective view of a wet cleaning memberincluding a single blade in a wet cleaning section of an additivemanufacturing apparatus according to one or more embodiments shown anddescribed herein;

FIG. 7D is a cross-sectional front view of a wet cleaning member in awet cleaning section of an additive manufacturing apparatus according toone or more embodiments shown and described herein;

FIG. 7E is a cross-sectional side view of a blade-less wet cleaningmember in a wet cleaning section of an additive manufacturing apparatusaccording to one or more embodiments shown and described herein;

FIG. 7F is a cross-sectional side view of a wet cleaning memberincluding two blades having different vertical positions in a wetcleaning section of an additive manufacturing apparatus according to oneor more embodiments shown and described herein;

FIG. 8 is a cross-sectional side view of a capping section of thecleaning station including a cap according to one or more embodimentsshown and described herein;

FIG. 9 is a process flow diagram of the fluid management system (binderpathway and the cleaning fluid pathway) according to one or moreembodiments shown and described herein;

FIG. 10 schematically depicts a bottom perspective view of a print headincluding a deflector plate according to one or more embodiments shownand described herein; and

FIG. 11 schematically depicts an end view of the deflector plate on theprint head according to one or more embodiments shown and describedherein.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments of additivemanufacturing apparatuses, and components thereof, examples of which areillustrated in the accompanying drawings. Whenever possible, the samereference numerals will be used throughout the drawings to refer to thesame or like parts. One embodiment of an additive manufacturingapparatus 100 comprising a cleaning station 110 is schematicallydepicted in FIG. 1 . The cleaning station 110 may generally include awet wipe cleaner section and a dry wipe cleaner section. The cleaningstation is in fluid communication with a cleaning fluid reservoir andapplies cleaning fluid to a print head to clean the print head. Variousembodiments of cleaning stations for additive manufacturing apparatuses,additive manufacturing apparatus comprising the cleaning stations, andmethods for using the same are described in further detail herein withspecific reference to the appended drawings.

Ranges can be expressed herein as from “about” one particular value,and/or to “about” another particular value. When such a range isexpressed, another embodiment includes from the one particular valueand/or to the other particular value. Similarly, when values areexpressed as approximations, by use of the antecedent “about,” it willbe understood that the particular value forms another embodiment. Itwill be further understood that the endpoints of each of the ranges aresignificant both in relation to the other endpoint, and independently ofthe other endpoint.

Directional terms as used herein—for example up, down, right, left,front, back, top, bottom—are made only with reference to the figures asdrawn and are not intended to imply ab solute orientation unlessotherwise expressly stated.

Unless otherwise expressly stated, it is in no way intended that anymethod set forth herein be construed as requiring that its steps beperformed in a specific order, nor that with any apparatus specificorientations be required. Accordingly, where a method claim does notactually recite an order to be followed by its steps, or that anyapparatus claim does not actually recite an order or orientation toindividual components, or it is not otherwise specifically stated in theclaims or description that the steps are to be limited to a specificorder, or that a specific order or orientation to components of anapparatus is not recited, it is in no way intended that an order ororientation be inferred, in any respect. This holds for any possiblenon-express basis for interpretation, including: matters of logic withrespect to arrangement of steps, operational flow, order of components,or orientation of components; plain meaning derived from grammaticalorganization or punctuation, and; the number or type of embodimentsdescribed in the specification.

As used herein, the singular forms “a,” “an” and “the” include pluralreferents unless the context clearly dictates otherwise. Thus, forexample, reference to “a” component includes aspects having two or moresuch components, unless the context clearly indicates otherwise.

During operation of an additive manufacturing apparatus, the efficacyand performance of the print head is essential. The print head isexposed to heat, and is also subject to excess build materialdistributed by a recoat head and/or binder material from the print head.The combination of these contaminants (i.e., excess build material andbinder material) can lead to clogged nozzles in the print head, whichcan adversely impact operation of the additive manufacturing apparatus.

The embodiments described herein are directed to additive manufacturingapparatuses and components for additive manufacturing apparatuses,specifically cleaning systems in additive manufacturing apparatuses,which may be used to conduct automated routine maintenance of theadditive manufacturing apparatuses to reduce or eliminate the presenceof clogged nozzles in the print head and other contamination.

Additive Manufacturing Apparatus

Referring now to FIG. 1 , an embodiment of an additive manufacturingapparatus 100 is schematically depicted. The apparatus 100 includes acleaning station 110, a build platform 120, and an actuator assembly102. The apparatus 100 may optionally include a supply platform 130. Theactuator assembly 102 comprises, among other elements, a recoat head 140for distributing build material 400 and a print head 150 for depositingbinder material 500. In embodiments, the recoat head 140 may furthercomprise an energy source for curing the binder material 500 as will bedescribed in further detail herein. The actuator assembly 102 may beconstructed to facilitate independent control of the recoat head 140 andthe print head 150 along the working axis 116 of the apparatus 100. Thisallows for the recoat head 140 and the print head 150 to traverse theworking axis 116 of the apparatus 100 in the same direction and/or inopposite directions and for the recoat head 140 and the print head 150to traverse the working axis of the apparatus 100 at different speedsand/or the same speed. Independent actuation and control of the recoathead 140 and the print head 150, in turn, allows for at least some stepsof the additive manufacturing process to be performed simultaneouslythereby reducing the overall cycle time of the additive manufacturingprocess to less than the sum of the cycle time for each individual step.In the embodiments of the apparatus 100 described herein, the workingaxis 116 of the apparatus 100 is parallel to the +/−X axis of thecoordinate axes depicted in the figures. It should be understood thatthe components of the additive manufacturing apparatus 100 traversingthe working axis 116, such as the recoat head 140, the print head 150,or the like, need not be centered on the working axis 116. However, inthe embodiments described herein, at least two of the components of theadditive manufacturing apparatus 100 are arranged with respect to theworking axis 116 such that, as the components traverse the working axis,the components could occupy the same or an overlapping volume along theworking axis if not properly controlled.

In the embodiment depicted in FIG. 1 , the apparatus 100 includes acleaning station 110, a build platform 120, a supply platform 130 and anactuator assembly 102. However, it should be understood that, in otherembodiments, the apparatus 100 does not include a supply platform 130,such as in embodiments where build material is supplied to the buildplatform 120 with, for example and without limitation, a build materialhopper. In the embodiment depicted in FIG. 1 , the cleaning station 110,the build platform 120, and the supply platform 130 are positioned inseries along the working axis 116 of the apparatus 100 between a printhome position 158 of the print head 150 located proximate an end of theworking axis 116 in the −X direction, and a recoat home position 148 ofthe recoat head 140 located proximate an end of the working axis 116 inthe +X direction. That is, the print home position 158 and the recoathome position 148 are spaced apart from one another in a horizontaldirection that is parallel to the +/−X axis of the coordinate axesdepicted in the figures and the cleaning station 110, the build platform120, and the supply platform 130 are positioned therebetween. In theembodiments described herein, the build platform 120 is positionedbetween the cleaning station 110 and the supply platform 130 along theworking axis 116 of the apparatus 100.

The cleaning station 110 is positioned proximate one end of the workingaxis 116 of the apparatus 100 and is co-located with the print homeposition 158 where the print head 150 is located or “parked” before andafter depositing binder material 500 on a layer of build material 400positioned on the build platform 120. The cleaning station 110 mayinclude one or more cleaning sections (not shown) to facilitate cleaningthe print head 150 between depositing operations. The cleaning sectionsmay include, for example and without limitation, a soaking stationcontaining a cleaning solution for dissolving excess binder material onthe print head 150, a wiping station for removing excess cleaning fluidfrom the print head 150, a jetting station for reestablishing a meniscuswithin the nozzles of the print head 150, a park station for maintainingmoisture in the nozzles of the print head 150, or various combinationsthereof. The print head 150 may be transitioned between the cleaningsections by the actuator assembly 102.

The build platform 120 is coupled to a lift system 800 comprising abuild platform actuator 122 to facilitate raising and lowering the buildplatform 120 relative to the working axis 116 of the apparatus 100 in avertical direction (i.e., a direction parallel to the +/−Z directions ofthe coordinate axes depicted in the figures). The build platformactuator 122 may be, for example and without limitation, a mechanicalactuator, an electro-mechanical actuator, a pneumatic actuator, ahydraulic actuator, or any other actuator suitable for imparting linearmotion to the build platform 120 in a vertical direction. Suitableactuators may include, without limitation, a worm drive actuator, a ballscrew actuator, a pneumatic piston, a hydraulic piston, anelectro-mechanical linear actuator, or the like. The build platform 120and build platform actuator 122 are positioned in a build receptacle 124located below the working axis 116 (i.e., in the −Z direction of thecoordinate axes depicted in the figures) of the apparatus 100. Duringoperation of the apparatus 100, the build platform 120 is retracted intothe build receptacle 124 by action of the build platform actuator 122after each layer of binder material 500 is deposited on the buildmaterial 400 located on build platform 120.

The supply platform 130 is coupled to a lift system 800 comprising asupply platform actuator 132 to facilitate raising and lowering thesupply platform 130 relative to the working axis 116 of the apparatus100 in a vertical direction (i.e., a direction parallel to the +/−Zdirections of the coordinate axes depicted in the figures). The supplyplatform actuator 132 may be, for example and without limitation, amechanical actuator, an electro-mechanical actuator, a pneumaticactuator, a hydraulic actuator, or any other actuator suitable forimparting linear motion to the supply platform 130 in a verticaldirection. Suitable actuators may include, without limitation, a wormdrive actuator, a ball screw actuator, a pneumatic piston, a hydraulicpiston, an electro-mechanical linear actuator, or the like. The supplyplatform 130 and supply platform actuator 132 are positioned in a supplyreceptacle 134 located below the working axis 116 (i.e., in the −Zdirection of the coordinate axes depicted in the figures) of theapparatus 100. During operation of the apparatus 100, the supplyplatform 130 is raised relative to the supply receptacle 134 and towardsthe working axis 116 of the apparatus 100 by action of the supplyplatform actuator 132 after a layer of build material 400 is distributedfrom the supply platform 130 to the build platform 120, as will bedescribed in further detail herein.

Referring now to FIGS. 1 and 2A, FIG. 2A schematically depicts theactuator assembly 102 of the additive manufacturing apparatus 100 ofFIG. 1 . The actuator assembly 102 generally comprises the recoat head140, the print head 150, a recoat head actuator 144, a print headactuator 154, and a support 182. In the embodiments described herein,the support 182 extends in a horizontal direction (i.e., a directionparallel to the +/−X direction of the coordinate axes depicted in thefigures) parallel to the working axis 116 (FIG. 1 ) of the apparatus100. When the actuator assembly 102 is assembled over the cleaningstation 110, the build platform 120, and the supply platform 130 asdepicted in FIG. 1 , the support 182 extends in a horizontal directionfrom at least the cleaning station 110 to beyond the supply platform130.

In one embodiment, the support 182 is a side of a rail 180 that extendsin a horizontal direction. For example, in one embodiment, the rail 180may be rectangular or square in vertical cross section (i.e., a crosssection in the Y-Z plane of the coordinate axes depicted in the figures)with a side surface of the rectangle or square forming the support 182.However, it should be understood that other embodiments are contemplatedand possible. For example and without limitation, the rail 180 may haveother cross sectional shapes, such as octagonal or the like, with thesupport 182 being one surface of facet of the rail 180. In embodiments,the support 182 is positioned in a vertical plane (e.g., a planeparallel to the X-Z plane of the coordinate axes depicted in thefigures). However, it should be understood that, in other embodiments,the support 182 is positioned in a plane other than a vertical plane.

In the embodiments described herein, the recoat head actuator 144 andthe print head actuator 154 are coupled to the support 182.

In the embodiments described herein, the recoat head actuator 144 isbi-directionally actuatable along a recoat motion axis 146 and the printhead actuator 154 is bi-directionally actuatable along a print motionaxis 156. That is, the recoat motion axis 146 and the print motion axis156 define the axes along which the recoat head actuator 144 and theprint head actuator 154 are actuatable, respectively. In embodiments,the recoat head actuator 144 and the print head actuator 154 arebi-directionally actuatable independent of one another. The recoatmotion axis 146 and the print motion axis 156 extend in a horizontaldirection and are parallel with the working axis 116 (FIG. 1 ) of theapparatus 100. In the embodiments described herein, the recoat motionaxis 146 and the print motion axis 156 are co-linear. With thisconfiguration, the recoat head 140 and the print head 150 may occupy thesame space (or portions of the same space) along the working axis 116 ofthe apparatus 100 at different times because the recoat motion axis 146and the print motion axis 156 lie along the same line. In the embodimentof the actuator assembly 102 depicted in FIGS. 2A-2C, the recoat motionaxis 146 and the print motion axis 156 are located in the same verticalplane. In embodiments where the support 182 is positioned in a verticalplane, the recoat motion axis 146 and the print motion axis 156 arelocated a vertical plane that is parallel to the vertical plane of thesupport 182, as depicted in FIGS. 2A-2C. However, it should beunderstood that other embodiments are contemplated and possible, such asembodiments in which the recoat motion axis 146 and the print motionaxis 156 are located in a vertical plane that is non-parallel with theplane of the support 182.

In the embodiments described herein, the recoat head actuator 144 andthe print head actuator 154 may be, for example and without limitation,mechanical actuators, electro-mechanical actuators, pneumatic actuators,hydraulic actuators, or any other actuator suitable for providing linearmotion. Suitable actuators may include, without limitation, worm driveactuators, ball screw actuators, pneumatic pistons, hydraulic pistons,electro-mechanical linear actuators, or the like. In one particularembodiment, the recoat head actuator 144 and the print head actuator 154are linear actuators manufactured by Aerotech® Inc. of Pittsburgh, Pa.,such as the PRO225LM Mechanical Bearing, Linear Motor Stage.

For example, the actuator assembly 102 may comprise a guide 184 affixedto the support 182 of the rail 180. The recoat head actuator 144 and theprint head actuator 154 may be moveably coupled to the rail 180 suchthat the recoat head actuator 144 and the print head actuator 154 canindependently traverse a length of the guide 184. In embodiments, themotive force traversing the recoat head actuator 144 and the print headactuator 154 is supplied by direct-drive linear motors, such asbrushless servomotors, for example.

In embodiments, the recoat head actuator 144, the print head actuator154, and the guide 184 may be a cohesive sub-system that is affixed tothe rail 180, such as when the recoat head actuator 144 and the printhead actuator 154 are similar to the PRO225LM Mechanical Bearing, LinearMotor Stages, for example. However, it should be understood that otherembodiments are contemplated and possible, such as embodiments where therecoat head actuator 144 and the print head actuator 154 comprisemultiple components that are individually assembled onto the rail 180 toform the recoat head actuator 144 and the print head actuator 154,respectively.

Still referring to FIGS. 2A-2C, the recoat head 140 is coupled to therecoat head actuator 144 such that the recoat head 140 is situatedproximate the working axis 116 (FIG. 1 ) of the additive manufacturingapparatus 100. Thus, bi-directional actuation of the recoat headactuator 144 along the recoat motion axis 146 affects bi-directionalmotion of the recoat head 140 on the working axis 116 of the additivemanufacturing apparatus 100. In the embodiment of the actuator assembly102 depicted in FIGS. 2A-2C, the recoat head 140 is coupled to therecoat head actuator 144 with strut 212 such that the recoat head 140 iscantilevered from the support 182 and positioned on the working axis 116(FIG. 1 ) of the additive manufacturing apparatus 100. Cantilevering therecoat head 140 from the support 182 allows the recoat head actuator 144and the guide 184 to be spaced apart from, for example, the buildplatform 120 of the additive manufacturing apparatus 100 therebyreducing the likelihood that the recoat head actuator 144, the guide184, and associate electrical components will be fouled or otherwisecontaminated with build material 400. This increases the maintenanceinterval for the recoat head actuator, increases the service life of therecoat head actuator, reduces machine downtime, and reduces build errorsdue to fouling of the recoat head actuator 144. In addition, spacing therecoat head actuator 144 apart from the build platform 120 of theapparatus 100 allows for improved visual and physical access to thebuild platform 120 and the supply platform 130, improving the ease ofmaintenance and allowing for better visual observation (from humanobservation, camera systems, or the like) of the additive manufacturingprocess. In some embodiments described herein, the recoat head 140 maybe fixed in directions orthogonal to the recoat motion axis 146 and theworking axis 116 (i.e., fixed along the +/−Z axis and/or fixed along the+/−Y axis).

In embodiments, the recoat head 140 may be pivotally coupled to therecoat head actuator 144. For example and without limitation, in theembodiment of the actuator assembly 102 depicted in FIGS. 2A-2C, thestrut 212 is coupled to the recoat head 140 and pivotally coupled to therecoat head actuator 144 at pivot point 214. This allows the recoat head140 to be pivoted with respect to the recoat head actuator 144 away fromthe working axis 116 (FIG. 1 ) of the apparatus 100 to facilitate, forexample, maintenance or removal of components of the apparatuspositioned below the recoat head 140 (e.g., the build receptacle, supplyreceptacle, or the like). In embodiments, the pivot point 214 mayinclude an actuator, such as a motor or the like, to facilitateautomated pivoting of the recoat head 140. In embodiments, a separateactuator (not depicted) may be provided between the recoat head 140 andthe recoat head actuator 144 to facilitate automated pivoting of therecoat head 140. While FIG. 2C depicts the pivot point 214 positionedbetween the strut 212 and the recoat head actuator 144, it should beunderstood that other embodiments are contemplated and possible, such asembodiments where the pivot point 214 is positioned between the strut212 and the recoat head 140.

Still referring to FIGS. 2A-2C, the print head 150 is coupled to theprint head actuator 154 such that the print head 150 is situatedproximate the working axis 116 (FIG. 2 ) of the additive manufacturingapparatus 100. Thus, bi-directional actuation of the print head actuator154 along the print motion axis 156 affects bi-directional motion of theprint head 150 on the working axis 116 of the additive manufacturingapparatus 100. In the embodiment of the actuator assembly 102 depictedin FIGS. 2A-2C, the print head 150 is coupled to the print head actuator154 with strut 216 such that the print head 150 is cantilevered from thesupport 182 and positioned on the working axis 116 (FIG. 1 ) of theadditive manufacturing apparatus 100. Cantilevering the print head 150from the support 182 allows the print head actuator 154 and the guide184 to be spaced apart from, for example, the build platform 120 of theadditive manufacturing apparatus 100 thereby reducing the likelihoodthat the print head actuator 154, the guide 184, and associateelectrical components will be fouled or otherwise contaminated withbuild material 400. This increases the maintenance interval for theprint head actuator, increases the service life of the print headactuator, reduces machine downtime, and reduces build errors due tofouling of the print head actuator 154. In addition, spacing the printhead actuator 154 apart from the build platform 120 of the apparatus 100allows for improved visual and physical access to the build platform 120and the supply platform 130, improving the ease of maintenance andallowing for better visual observation (from human observation, camerasystems, or the like) of the additive manufacturing process. In someembodiments described herein, the print head 150 may be fixed indirections orthogonal to the recoat motion axis 146 and the working axis116 (i.e., fixed along the +/−Z axis and/or fixed along the +/−Y axis).

In embodiments, the print head 150 may be pivotally coupled to the printhead actuator 154. For example and without limitation, in the embodimentof the actuator assembly 102 depicted in FIGS. 2A-2C, the strut 216 iscoupled to the print head 150 and pivotally coupled to the print headactuator 154 at pivot point 218. This allows the print head 150 to bepivoted with respect to the print head actuator 154 away from theworking axis 116 (FIG. 1 ) of the apparatus 100 to facilitate, forexample, maintenance or removal of components of the apparatuspositioned below the print head 150 (e.g., the build receptacle, supplyreceptacle, or the like). In embodiments, the pivot point 218 mayinclude an actuator, such as a motor or the like, to facilitateautomated pivoting of the print head 150. In embodiments, a separateactuator (not depicted) may be provided between the print head 150 andthe print head actuator 154 to facilitate automated pivoting of theprint head 150. While FIG. 2B depicts the pivot point 218 positionedbetween the strut 216 and the print head actuator 154, it should beunderstood that other embodiments are contemplated and possible, such asembodiments where the pivot point 218 is positioned between the strut216 and the print head 150.

In embodiments, the recoat head actuator 144 and the print head actuator154 overlap over the build receptacle 124. As such, the range of motionof the recoat head actuator 144 (and attached recoat head 140) and theprint head actuator 154 (and attached print head 150) also overlap overthe build receptacle 124. In embodiments, the range of motion of therecoat head actuator (and attached recoat head 140) is greater than therange of motion of the print head actuator 154 (and attached print head150). This is true when, for example, the apparatus 100 includes asupply receptacle 134 positioned between the build receptacle 124 andthe recoat home position 148. However, it should be understood thatother embodiments are contemplated and possible. For example, inembodiments (not depicted) the recoat head actuator 144 and the printhead actuator 154 may overlap along the entire length of the workingaxis 116 of the apparatus 100. In these embodiments, the range of motionof the recoat head actuator 144 (and attached recoat head 140) and theprint head actuator 154 (and attached print head 150) are co-extensiveover the working axis 116 of the apparatus 100.

As noted above, in the embodiments described herein the recoat head 140and the print head 150 are both located on the working axis 116 of theapparatus 100. As such, the movements of the recoat head 140 and theprint head 150 on the working axis 116 occur along the same axis and arethus co-linear. With this configuration, the recoat head 140 and theprint head 150 may occupy the same space (or portions of the same space)along the working axis 116 of the apparatus 100 at different timesduring a single build cycle. The recoat head 140 and the print head 150may be moved along the working axis 116 of the apparatus 100simultaneously in a coordinated fashion, in the same direction and/or inopposing directions, at the same speeds or different speeds. This, inturn, allows for individual steps of the additive manufacturing process,such as the distributing step (also referred to herein as the recoatingstep), the depositing step (also referred to herein as the printingstep), the curing (or heating) step, and/or the cleaning step to beperformed with overlapping cycle times. For example, the distributingstep may be initiated while the cleaning step is being completed; thedepositing step may be initiated while the distributing step incompleted; and/or the cleaning step may be initiated while thedistributing step is being completed. This may reduce the overall cycletime of the additive manufacturing apparatus 100 to less than the sum ofthe distributing cycle time (also referred to herein as the recoat cycletime), the depositing cycle time (also referred to herein as the printcycle time), and/or the cleaning cycle time.

Other embodiments of an actuator assembly (not shown) may be implementedin the embodiments of the additive manufacturing apparatuses 100depicted in FIG. 1 , for example, as an alternative to the actuatorassembly 102. As such, it should be understood that other embodiments ofthe actuator assembly may be utilized to build an object on the buildplatform 120 in a similar manner as described herein with respect toFIGS. 1-2C.

Referring now to FIGS. 1-2C, in the embodiments described herein, theprint head 150 may deposit the binder material 500 on a layer of buildmaterial 400 distributed on the build platform 120 through an array ofnozzles 172 located on the underside of the print head 150 (i.e., thesurface of the print head 150 facing the build platform 120). Inembodiments, the array of nozzles 172 are spatially distributed in theXY plane of the coordinate axes depicted in the figures. In someembodiments, the print heads may also define the geometry of the partbeing built. In embodiments, the nozzles 172 may be piezoelectric printnozzles and, as such, the print head 150 is a piezo print head. Inalternative embodiments, the nozzles 172 may be thermal print nozzlesand, as such, the print head 150 is a thermal print head. In alternativeembodiments, the nozzles 172 may be spray nozzles.

In addition to the nozzles 172, in some embodiment, the print head 150may further comprise one or more sensors (not depicted) for detecting aproperty of the build material 400 distributed on the build platform 120and/or the binder material 500 deposited on the build platform 120.Examples of sensors may include, without limitation, image sensors suchas cameras, thermal detectors, pyrometers, profilometers, ultrasonicdetectors, and the like. In these embodiments, signals from the sensorsmay be fed back to the control system (described in further detailherein) of the additive manufacturing apparatus to facilitate feedbackcontrol of one or more functions of the additive manufacturingapparatus.

Alternatively or additionally, the print head 150 may comprise at leastone energy source (not depicted). The energy source may emit awavelength or a range of wavelengths of electromagnetic radiationsuitable for curing (or at least initiating curing) the binder material500 deposited on the build material 400 distributed on the buildplatform 120. For example, the energy source may comprise an infraredheater or an ultraviolet lamp which emit wavelengths of infrared orultraviolet electromagnetic radiation suitable for curing the bindermaterial 500 previously deposited on the layer of build material 400distributed on the build platform 120. In instances where the energysource is an infrared heater, the energy source may also preheat thebuild material 400 as it is distributed from the supply platform 130 tothe build platform 120 that may assist in expediting the curing ofsubsequently deposited binder material 500.

As noted herein, the recoat head 140 is used in the additivemanufacturing apparatus 100 to distribute build material 400 and, morespecifically, to distribute build material 400 from the supply platform130 to the build platform 120. That is, the recoat head 140 is used to“recoat” the build platform 120 with build material 400. It iscontemplated that the recoat head 140 may include at least one of aroller, blade, or wiper to facilitate the distribution of build material400 from the supply platform 130 to the build platform 120.

In embodiments, the recoat head 140 may further comprise at least oneenergy source. In these embodiments, the energy source(s) may emit awavelength or a range of wavelengths of electromagnetic radiationsuitable for curing (or at least initiating curing) the binder material500 deposited on the build material 400 distributed on the buildplatform 120. For example, the energy source may comprise an infraredheater or an ultraviolet lamp which emit wavelengths of infrared orultraviolet electromagnetic radiation, respectively, suitable for curingthe binder material 500 previously deposited on the layer of buildmaterial 400 distributed on the build platform 120. In instances wherethe energy source is an infrared heater, the energy source may alsopreheat the build material 400 as it is distributed from the supplyplatform 130 to the build platform 120 that may assist in expediting thecuring of subsequently deposited binder material 500.

In some embodiments, the recoat head 140 may further comprise at leastone sensor, such as at least one sensor for detecting a property of thebuild material 400 distributed on the build platform 120 and/or thebinder material 500 deposited on the build platform 120. Examples ofsensors may include, without limitation, image sensors such as cameras,thermal detectors, pyrometers, profilometers, ultrasonic detectors, andthe like. In these embodiments, signals from the sensors may be fed backto the control system (described in further detail herein) of theadditive manufacturing apparatus to facilitate feedback control of oneor more functions of the additive manufacturing apparatus.

Referring now to FIGS. 1 and 3 , FIG. 3 schematically depicts a portionof a control system 200 for controlling the additive manufacturingapparatus 100 of FIG. 1 with an actuator assembly as depicted in FIGS.2A-2C. The control system 200 is communicatively coupled to the recoathead actuator 144, the print head actuator 154, the build platformactuator 122, and the supply platform actuator 132. The control system200 may also be communicatively coupled to the print head 150 and therecoat head 140. In embodiments where additional accessories orcomponents are included, such as process accessories, process accessoryactuators, and sensors (not depicted), the control system 200 may alsobe communicatively coupled to the additional components. In theembodiments described herein, the control system 200 comprises aprocessor 202 communicatively coupled to a memory 204. The processor 202may include any processing component(s), such as a central processingunit or the like, configured to receive and execute computer readableand executable instructions stored in, for example, the memory 204. Inthe embodiments described herein, the processor 202 of the controlsystem 200 is configured to provide control signals to (and therebyactuate) the recoat head actuator 144, the print head actuator 154, thebuild platform actuator 122, the supply platform actuator 132, and anyadditional components (when included). The processor 202 may also beconfigured to provide control signals to (and thereby actuate) the printhead 150 and the recoat head 140. The control system 200 may also beconfigured to receive signals from one or more sensors of the recoathead 140 and, based on these signals, actuate one or more of the recoathead actuator 144, the print head actuator 154, the build platformactuator 122, the supply platform actuator 132, the print head 150,and/or the recoat head 140.

In the embodiments described herein, the computer readable andexecutable instructions for controlling the additive manufacturingapparatus 100 are stored in the memory 204 of the control system 200.The memory 204 is a non-transitory computer readable memory. The memory204 may be configured as, for example and without limitation, volatileand/or nonvolatile memory and, as such, may include random access memory(including SRAM, DRAM, and/or other types of random access memory),flash memory, registers, compact discs (CD), digital versatile discs(DVD), and/or other types of storage components.

The operation of the additive manufacturing apparatus 100 will now bedescribed in further detail with specific reference to FIGS. 1, 3, and2A-2C.

Referring to FIG. 1 , the additive manufacturing apparatus 100 isschematically depicted at initiation of a build cycle. The phrase “buildcycle,” as used herein, refers to the process of building a single layerof an object on the build platform 120. In the embodiments describedherein, the “build cycle” may include one iteration each of raising thesupply platform 130, lowering the build platform 120, distributing a newlayer of build material 400 from the supply platform 130 to the buildplatform 120, depositing binder material 500 on the new layer of buildmaterial 400 distributed on the build platform 120, and optionally thecleaning of the print head 150.

In describing the operation of the additive manufacturing apparatus 100,specific reference will be made herein to build material 400 and bindermaterial 500. The build material generally comprises a powder materialthat is spreadable or flowable. Categories of suitable powder materialinclude, without limitation, dry powder material and wet powder material(e.g., a powder material entrained in a slurry). In embodiments, thebuild material may be capable of being bound together with the bindermaterial. In embodiments, the build material may also be capable ofbeing fused together, such as by sintering. In embodiments, the buildmaterial may be an inorganic powder material including, for example andwithout limitation, ceramic powders, metal powders, glass powders,carbon powder, sand, cement, calcium phosphate powder, and variouscombinations thereof. In embodiments, the build material may comprise anorganic powder material including, for example and without limitation,plastic powders, polymer powders, soap, powders formed from foodstuff(i.e., edible powders), and various combinations thereof. In someembodiments, the build material may be (or include) pharmaceuticallyactive components, such as when the build material is or contains apharmaceutical. In embodiments, the build material may be a combinationof inorganic powder material and organic powder material.

The build material may be uniform in size or non-uniform in size. Inembodiments, the build material may have a powder size distribution suchas, for example and without limitation, a bi-modal or tri-modal powdersize distribution. In embodiments, the build material may be, or mayinclude, nanoparticles.

The build material may be regularly or irregularly shaped, and may havedifferent aspect ratios or the same aspect ratio. For example, the buildmaterial may take the form of small spheres or granules, or may beshaped like small rods or fibers.

In embodiments, the build material can be coated with a second material.For example and without limitation, the build material may be coatedwith a wax, a polymer, or another material that aids in binding thebuild material together (in conjunction with the binder). Alternativelyor additionally, the build material may be coated with a sintering agentand/or an alloying agent to promote fusing the build material.

The binder material may comprise a material which is radiant-energycurable and which is capable of adhering or binding together the buildmaterial when the binder material is in the cured state. The term“radiant-energy curable,” as used herein, refers to any material thatsolidifies in response to the application of radiant energy of aparticular wavelength and energy. For example, the binder material maycomprise a known photopolymer resin containing photo-initiator compoundsfunctioning to trigger a polymerization reaction, causing the resin tochange from a liquid state to a solid state. Alternatively, the bindermaterial may comprise a material that contains a solvent that may beevaporated out by the application of radiant energy. The uncured bindermaterial may be provided in solid (e.g., granular) form, liquid formincluding a paste or slurry, or a low viscosity solution compatible withprint heads. The binder material may be selected to have the ability toout-gas or burn off during further processing, such as during sinteringof the build material. In embodiments, the binder material may be asdescribed in U.S. Patent Publication No. 2018/0071820 entitled“Reversible Binders For Use In Binder Jetting Additive ManufacturingTechniques” and assigned to General Electric Corporation, Schenectady,N.Y. However, it should be understood that other binder materials arecontemplated and possible, including combinations of various bindermaterials.

Referring initially to FIG. 1 , at initiation of the build cycle, thecontrol system 200 sends a control signal to the supply platformactuator 132 that actuates the supply platform actuator 132 in theupward vertical direction (i.e., in the +Z direction of the coordinateaxes depicted in the figures) as indicated by arrow 316, thereby movingthe supply platform 130, and the build material 400 positioned thereon,in the upward vertical direction towards the working axis 116 of theapparatus 100. The supply platform 130 is moved in the upward verticaldirection by an amount sufficient to position a predetermined amount ofthe build material 400 in the pathway of the recoat head 140 as ittraverses over the working axis 116 of the apparatus 100. While FIG. 1schematically depicts an initiation of a build cycle in which bindermaterial 500 is already present on a layer of build material 400 (suchas on a previously distributed layer of build material 400), it shouldbe understood that the initiation of the build cycle may occur withoutany build material 400 or binder material 500 disposed on the buildplatform 120.

While FIGS. 1 and 2A-2C schematically depict an embodiment of anactuator assembly 102, it should be understood that other embodimentsare contemplated and possible, such as embodiments different number ofsupports and/or actuators. Moreover, it is contemplated that embodimentsmay include a multiple supports, each having one of the recoat headactuator 144 and the print head actuator 154 mounted thereto.

Cleaning Station

Turning now to FIGS. 4A-4D, an embodiment of the cleaning station 110 isshown in greater detail. Although described in various embodiments asbeing associated with the additive manufacturing apparatus 100 of FIGS.1 and 2A-2C, it is contemplated that the cleaning station 110 and fluidmanagement system coupled thereto may be used with other types ofadditive manufacturing and printing apparatuses known and used in theart.

The cleaning station 110 may comprise a cleaning station vessel 314positioned about a binder purge bin 302, a purge wiper section 303, awet cleaner section 304, a dry wiper section 306, a spit capture tray307, and a capping section 308. In various embodiments, the purge wipersection 303, the wet cleaner section 304, the dry wiper section 306, thespit capture tray 307, and the capping section 308 are positioned abovethe cleaning station vessel 314, each containing a volume of cleaningfluid. As will be described in greater detail below, the cleaningstation vessel 314 is configured to collect cleaning fluid overflowingfrom these sections and provide the collected cleaning fluid to acleaning fluid receptacle.

As shown in FIGS. 4A-4C, the cleaning station 110 includes a binderpurge bin 302, which is configured to receive material, such ascontaminants and binder material, discharged by the print head. Inembodiments, the cleaning station 110 additionally includes a purgewiper section 303 positioned between the binder purge bin 302 and thewet cleaner section 304. The purge wiper section 303 includes a purgewipe member 313 which contacts the print head after contaminants andbinder material are discharged into the binder purge bin 302 to removeremaining contaminants and binder material from the face of the printhead before the print head is introduced to the wet cleaner section 304.In embodiments, the purge wipe member 313 redirects the loosecontaminants and binder material into the binder purge bin 302 fordisposal (as shown in FIGS. 4B and 4C), thereby reducing the amount ofcontaminants and binder material introduced into the cleaning stationvessel 314 during the cleaning process. In embodiments, the binder purgebin 302 includes a drain 301 through which the binder purge bin 302 isfluidly coupled to a binder reservoir 802 or waste reservoir 814 (FIG. 9).

The purge wiper section 303 further includes a purge wipe reservoir 315.In embodiments, the purge wipe reservoir 315 is positioned verticallybelow the purge wipe member 313 and maintains a volume of cleaning fluidthrough which the purge wipe member 313 is rotated for cleaning thepurge wipe member 313. By maintaining a suitable volume of cleaningfluid located for contact with the purge wipe member 313, the purge wipereservoir 315 may reduce a total amount of cleaning fluid utilized bythe cleaning station 110, as compared to cleaning stations including alarge tank of cleaning fluid for use by multiple cleaning components.

The wet cleaner section 304 applies cleaning fluid to the print head,specifically, a faceplate of the print head. In embodiments, the wetcleaner section 304 includes a stationary wet cleaning member 310 (asshown in FIGS. 4A-4C and 7A-7F), although in other embodiments, the wetcleaner section 304 can include a rotating or Z-actuating wet cleaningmember 310 a (as shown in FIG. 5 ).

The dry wiper section 306, which in some embodiments is downstream ofthe wet cleaner section 304, removes excess liquid (e.g., cleaning fluidand contaminants) from the print head in advance of binder jetting.Similar to the purge wiper section 303, the dry wiper section 306includes a dry wipe member 312 which contacts the print head aftercleaning fluid is applied to the print head by the wet cleaning member310 to remove contaminants and binder material dissolved by the cleaningfluid, as well as excess cleaning fluid, from the face of the print headbefore the print head prints another layer of binder material. The drywiper section 306 further includes a dry wipe reservoir 317. Inembodiments, the dry wipe reservoir 317 is positioned vertically belowthe dry wipe member 312 and maintains a volume of cleaning fluid throughwhich the dry wipe member 312 is rotated for cleaning the dry wipemember 312. By maintaining a suitable volume of cleaning fluid locatedfor contacting the dry wipe member 312, the dry wipe reservoir 317 mayreduce a total amount of cleaning fluid utilized by the cleaning station110, as compared to cleaning stations including a large tank of cleaningfluid for use by multiple cleaning components. In embodiments, the drywiper section 306 and the purge wiper section 303 may have the same orsimilar construction. As shown in FIGS. 4A-4C, the dry wiper section 306is located between the wet cleaner section 304 and the spit capture tray307 along the +/−X direction in the FIGS. and parallel to the workingaxis 116.

The spit capture tray 307 collects an amount of binder material ejectedby the print head as it prepares for printing. For example, inembodiments, the print head ejects a small amount of binder material asit is primed to printing and re-establishes the meniscus at each nozzleneeded to ensure that the binder material is properly ejected duringprinting operations. In embodiments, the spit capture tray 307 maintainsa volume of liquid (e.g., cleaning fluid or binder material) into whichthe binder material from the print head is ejected. It is believed thatthe volume of liquid provides improved retention of the binder materialthat is ejected from the print head since the binder material is ejectedin such small volumes that it may otherwise aerosolize and be caught inthe air flow path generated during movement of the print head. Inembodiments, the spit capture tray 307 includes a first side wall 307 aand a second side wall 307 b that is parallel to the first side wall 307a. A bottom wall 307 c extends between and separates the first side wall307 a and the second side wall 307 b. In embodiments, a height of thefirst side wall 307 a is less than a height of the second side wall 307b. Alternatively, the height of the second side wall 307 b may be lessthan the height of the second side wall 307 b. Such a constructionenables the volume of liquid (and the binder material ejected into thespit capture tray 307) to flow over the side wall having the lowerheight and into the cleaning station vessel 314. However, inembodiments, the first side wall 307 a has a height that is equal to aheight of the second side wall 307 b. In such embodiments, the volume ofliquid (and the binder material ejected into the spit capture tray 307)flows over both of the side walls. Accordingly, in embodiments in whichthe side walls are of equal height, the spit capture tray 307 may beself-cleaning, as the cleaning fluid continually flows over the walls toclean the spit capture tray 307. Alternatively, in embodiments, the spitcapture tray 307 may include at least one fluid outlet (not shown)through which the liquid can flow out of the spit capture tray 307.Accordingly, in some such embodiments, the liquid can be recycled, suchas by connecting the fluid outlet to the cleaning fluid reservoir 816 orbinder reservoir 802 (FIG. 9 ), or sent to a waste reservoir 814 (FIG. 9).

In embodiments, the spit capture tray 307 includes at least one fluidinlet 309 through which cleaning fluid is provided to the spit capturetray 307. As shown in the embodiment in FIGS. 4A and 4B, the spitcapture tray 307 includes two fluid inlets 309 positioned in the bottomwall 307 c of the spit capture tray 307, although it is contemplatedthat, in other embodiments, the fluid inlet(s) 309 can be positioned inthe first side wall 307 a, the second side wall 307 b, or lateral wallsextending between the first side wall and the second side wall (notshown). In embodiments in which two or more fluid inlets are included,each fluid inlet may be in the same wall as the other fluid inlet(s), orin a different wall than the other fluid inlet(s). As will be describedin greater detail below, cleaning fluid is provided to the fluidinlet(s) 309 by the cleaning fluid reservoir 816 (FIG. 9 ).

The capping section 308, which may be also considered an idle section,is a location where the print head may be temporarily placed in advanceof binder jetting. In embodiments, the capping section 308 suppliescleaning fluid to the print head faceplate to prevent binder from dryingon the print head. Without being limited to theory, maintaining thepurge wiper section 303, wet cleaner section 304, the dry wiper section306, the spit capture tray 307, and the capping section 308 within asingle cleaning station vessel 314 is highly advantageous as itstreamlines cleaning fluid management by eliminating the need to controlthree separate cleaning station vessels. In this embodiment, cleaningfluid maintenance is limited to a single cleaning station vessel 314.

Moreover, as shown in FIGS. 4B-4D, in embodiments, a bottom surface 321of the cleaning station vessel 314 is sloped or angled in two directions(e.g., in the X and Y directions) to direct cleaning fluid to a maincleaning vessel drain 320. In other words, the bottom surface is angledwith respect to a horizontal plane and with respect to a vertical plane.The main cleaning vessel drain 320 is positioned at a point within thecleaning station vessel that is the lowest vertical point of thecleaning station vessel. Accordingly, the cleaning fluid may becontinuously pumped into the purge wiper section 303, the wet cleanersection 304, the dry wiper section 306, and the spit capture tray 307and flow into the cleaning station vessel 314. When the cleaning fluidin the cleaning station vessel 314 reaches the main cleaning vesseldrain 320, the cleaning fluid flows through the main cleaning vesseldrain 320 and is returned to a cleaning fluid reservoir, as will bediscussed in greater detail below. The main cleaning vessel drain 320may be, for example, a passive drain that enables the cleaning fluid toflow through it, or an active drain that actively removes the cleaningfluid from the cleaning station vessel 314. It should be understoodthat, although not shown in FIGS. 4B-4D, the main cleaning vessel drain320 is in fluid communication with a cleaning fluid reservoir, such asthrough piping or tubing and filters. In embodiments, the cleaningstation vessel 314 is sized to contain a volume of fluid that is greaterthan or equal to a maximum amount of fluid that can be supplied to theadditive manufacturing apparatus 100. For example, the cleaning stationvessel 314 may be sized to receive and contain at least the volume ofcleaning fluid contained in the cleaning fluid reservoir and in thebinder material reservoir such that, in the event of a failure, allfluid in the machine can be retained within the cleaning station vessel314.

In embodiments, the cleaning station vessel 314 is in fluidcommunication with an overflow vessel 318, as shown in FIGS. 4B-4D, suchas through an overflow drain 323. The overflow drain 323 enablescleaning fluid that accumulates within the cleaning station vessel 314to be removed from the cleaning station vessel 314 through analternative flow path. For example, if the main cleaning vessel drain320 becomes clogged, cleaning fluid may accumulate within the cleaningstation vessel 314 to a liquid height that is greater than a verticalposition of the top of the overflow drain 323. Accordingly, additionalfluid may flow through the overflow drain 323 and into the overflowvessel 318. As shown in FIGS. 4B-4D, the overflow vessel 318 includes atleast one overflow vessel drain 322. In embodiments, cleaning fluid thatis drained from the cleaning station vessel 314 into the overflow vessel318 is drained from the overflow vessel 318 through the at least oneoverflow vessel drain 322, where it may be recombined with the cleaningfluid drained from the main cleaning vessel drain 320 and provided tothe cleaning fluid reservoir 816 (FIG. 9 ). The at least one overflowvessel drain 322 may be, for example, a passive drain that enables thecleaning fluid to flow through it, or an active drain that activelyremoves the cleaning fluid from the overflow vessel 318. It should beunderstood that, although not shown in FIGS. 4B-4D, the at least oneoverflow vessel drain 322 is in fluid communication with a cleaningfluid reservoir, such as through piping or tubing. In embodiments, theoverflow vessel 318 is sized to contain a volume of fluid that isgreater than or equal to a maximum amount of fluid that can be suppliedto the additive manufacturing apparatus 100. For example, the overflowvessel 318 may be sized to receive and contain at least the volume ofcleaning fluid contained in the cleaning fluid reservoir and in thebinder material reservoir such that, in the event of a failure, allfluid in the machine can be retained within the overflow vessel 318.

As can be seen in FIGS. 4B-4D, in embodiments, various components of thecleaning station 110 are mounted to a cleaning station frame 300. Thecleaning station frame 300 enables the various components of thecleaning station 110, including the binder purge bin 302, the purgewiper section 303, the wet cleaner section 304, the dry wiper section306, the spit capture tray 307, and the capping section 308 to beoriented and aligned with respect to one another and mounted within theadditive manufacturing apparatus 100. In embodiments, the cleaningstation frame 300 is coupled to feet 305. The feet 305 can enable thecomponents of the cleaning station components to be mounted to thecleaning station frame 300, properly aligned, and/or tested on a benchor other worktop surface before being mounted within the additivemanufacturing apparatus 100. Accordingly, in embodiments, the cleaningstation frame 300 and the feet 305 can be used to associate the variouscomponents of the cleaning station 110 into a module that can beinstalled into and removed from the additive manufacturing apparatus.

In various embodiments, the cleaning station 110 further includes a topplate 501. The top plate 501, as shown in FIG. 4A, provides a surfacethrough which the cleaning station 110 can be mounted within theadditive manufacturing apparatus. Additionally, in embodiments, the topplate 501 may prevent build material and fluids (including, for example,cleaning fluid and binder material) from being deposited in other areasof the apparatus, such as between the cleaning station 110 and theworking surface of the additive manufacturing apparatus 100.

In the embodiment shown in FIGS. 4A and 4D, a cover plate 502 ispositioned along the length of the cleaning station 110 (in the +/−Xdirection in the FIGS.) from one end of the top plate 501 to theopposite end of the top plate 501. In embodiments, the cover plate 502covers mounting and motion components of the various sections of thecleaning station 110 to prevent fluids from contacting such components,and redirects any fluids contacting the cover plate 502 into thecleaning station vessel 314. As shown in FIG. 4D, in embodiments, thecover plate 502 may be mounted to an interior of the overflow vessel318, pass through, for example, a slot formed in the top plate 501,extend over the mounting and motion components, and is mounted to aninterior of the cleaning station vessel 314. In embodiments, the coverplate 502 may be mounted directly to the cleaning station vessel 314, orthe cover plate 502 may be mounted to the cleaning station vessel 314indirectly, such as through one or more linking components positionedbetween the cover plate 502 and the cleaning station vessel 314.However, it is contemplated that some embodiments may not include thecover plate 502.

FIG. 5 depicts an alternative embodiment of a cleaning station, referredto in FIG. 5 as cleaning station 110 a. Like cleaning station 110, thecleaning station 110 a includes a binder purge bin 302 a, a purge wipersection 303 a, a wet cleaner section 304 a, a dry wiper section 306 a,and a spit capture tray 307. The cleaning station 110 a does not includea capping section 308, although in embodiments, a capping section 308may be included. As shown in FIG. 5 , the binder purge bin 302 a may beconsidered to be a section of the cleaning station vessel 314 a of thecleaning station 110 a, although it is constructed to contain a volumedistinct from a volume contained by the cleaning station vessel 314 a.In embodiments, the binder purge bin 302 a may overflow into thecleaning station vessel 314 a, and/or the cleaning station vessel 314 amay overflow into the binder purge bin 302 a.

In contrast to the embodiment depicted in FIGS. 4A-4C, in FIG. 5 , thecleaning station 110 a includes a wet cleaner section 304 a thatincludes a wet cleaning member 310 a. The wet cleaning member 310 a is arotating wipe member, similar in construction to purge wipe member 313and/or dry wipe member 312, described above and below. However, incontrast to the purge wipe member 313 and the dry wipe member 312, thewet cleaning member 310 a includes a fluid channel (shown as fluidchannels 408 a, 408 b, 408 c, and 408 d in FIG. 5 and generally referredto as fluid channel 408) extending along a length of the wet cleaningmember 310 a (e.g., in the +/−Y direction in the FIGS.) for providingcleaning fluid to the face of the print head. Accordingly, as the wetcleaning member 310 a rotates, cleaning fluid may be filled in the fluidchannel 408 (e.g., fluid channel 408 a) or emptied from the fluidchannel 408 (e.g., fluid channels 408 b and 408 c) to clean the wetcleaning member 310 a. In embodiments, the wet cleaning member 310 aincludes a cleaning manifold 414 that is fluidly coupled to the cleaningfluid supply (not shown) and to the fluid channel 408, such that thecleaning manifold 414 receives cleaning fluid from the cleaning fluidsupply and supplies the cleaning fluid to the fluid channel 408.

The cleaning station 110 a also includes a dry wiper section 306 a. Incontrast to the dry wiper section 306 in FIGS. 4A-4C, the dry wipersection 306 a includes the dry wipe member 312, but does not include adry wiper reservoir. In particular, in the embodiment shown in FIG. 5 ,the dry wipe member 312 may be cleaned through contact with the wetcleaning member 310 a. In particular, the dry wipe member 312 rotates ina direction opposite of a direction of rotation of the wet cleaningmember 310 a such that wiper blades from the dry wipe member 312 and thewet cleaning member 310 a engage with one another and the cleaning fluidfrom the fluid channel being emptied (e.g., fluid channel 408 b)contacts the wiper blades of the dry wipe member 312. Accordingly, thewet cleaning member 310 a may serve the function of the dry wiperreservoir by providing a volume of cleaning fluid to clean the dry wipemember 312.

It should be understood that, in embodiments, cleaning station 110 a canbe substituted for cleaning station 110, and elements included incleaning station 110 a can be used in cleaning station 110, and viceversa. Accordingly, although depicted as separate embodiments, it iscontemplated that embodiments may incorporate features from one or bothof the cleaning stations 110 and 110 a.

Referring again to FIGS. 1 and 2A, in the embodiments described herein,the print head 150 may deposit the binder material 500 on a layer ofbuild material 400 distributed on the build platform 120 through anarray of nozzles 172 located on the underside of the print head 150(i.e., the surface of the print head 150 facing the build platform 120).In one or more embodiments, the nozzles 172 may be piezoelectric printnozzles and, as such, the print head 150 is a piezo print head. Inalternative embodiments, the nozzles 172 may be thermal print nozzlesand, as such, the print head 150 is a thermal print head.

In general, after the print head 150 has deposited the binder material500 on the layer of build material 400 positioned on the build platform120 (FIG. 1 ), it is moved to the binder purge bin 302, wherecontaminants are dislodged via backpressure and, in embodiments, usingbinder material 500 ejected from the nozzles 172. Next, the print head150 is wiped by the purge wipe member 313 as it is moved through thepurge wiper section 303 from the binder purge bin 302 toward the wetcleaner section 304 to direct loose contaminants and binder materialfrom the face of the print head 150 into the binder purge bin 302. Next,the print head 150 is moved to the wet cleaner section 304 where acleaning fluid is applied to the print head 150. The print head 150 isthen moved to the dry wiper section 306 where the cleaning fluid andremaining contaminants are removed, before the print head 150 is movedto the spit capture tray 307. At the spit capture tray 307, anyremaining contaminants are dislodged and the binder meniscus isreestablished by ejecting binder material 500 from the nozzles 172. Inembodiments in which the print head 150 is idle, instead of moving tothe spit capture tray 307, the print head 150 may be moved to thecapping section 308 where it is kept moist to prevent the bindermaterial from drying out and clogging the nozzles 172 of the print head150. Each of the sections of the cleaning station 110 will now bedescribed in greater detail.

Cleaning Station—Dry Wipe Cleaner Section and Purge Wiper Section

Various suitable embodiments are contemplated for the dry wiper section306 and the purge wiper section 303. In particular, the dry wipersection 306 and the purge wiper section 303 may include identical orsimilar features and/or may include features that are different fromeach other. Accordingly, in embodiments described herein, reference willbe made to the dry wiper section 306 its corresponding components, andit should be understood that the description equally applies to thepurge wiper section 303 and its corresponding components.

Referring to the embodiments depicted in FIGS. 4A-4D, the dry wipersection 306 comprises a dry wipe member 312 and a dry wipe reservoir317. The dry wipe member 312 includes a dry wiper body 515 having atleast one wiper blade 516 extending radially therefrom. In embodiments,such as the embodiments shown in FIGS. 5 and 6A-6H, the dry wiper body515 has a predetermined number of planar faces 517, and each wiper blade516 extends radially from one of the planar faces 517. The number ofplanar faces 517 can vary depending on the particular embodiments. Forexample, in embodiments, the dry wiper body 515 can include 1, 2, 3, 4,5, 6, or more planar faces 517. However, it is contemplated that, inembodiments, the dry wiper body 515 can have a circular cross-section,and may not include planar faces, as shown in FIGS. 4A-4C. Moreover, thenumber of wiper blades extending from each planar face 517, and thetotal number of wiper blades extending from the dry wipe member 312 canvary depending on the particular embodiment. For example, in theembodiments shown in FIGS. 4B and 4C, wiper blades 516 are positioned inpairs with two wiper blades 516 positioned at each of three locationsaround the circumference of the dry wiper body 515 such that the drywipe member 312 includes 6 wiper blades. As another example, in theembodiments shown in FIGS. 5 and 6 , each dry wiper body 515 includesfour planar faces 517, and each planar face 517 includes two wiperblades 516 extending therefrom, for a total of eight wiper blades 516per dry wipe member 312. The wiper blades 516 can be mounted to the drywiper body 515 in any suitable manner, including, but not limited toadhering the wiper blades 516 to the surface of the dry wiper body 515,mating features that enable the wiper blades 516 to be received by thedry wiper body 515 (such as those shown and described with respect tothe wet cleaning member 310 described hereinbelow), or the like.

As shown in the FIGS., in embodiments, the dry wipe member 312 includesvarious groups of wiper blades 516. Each group of wiper blades 516 caninclude from one to five wiper blades 516, with the groups being equallyspaced around the outer surface of the dry wiper body 515. For example,when three groups of wiper blades are included, each group is locatedabout 120° from each of the other groups; when four groups of wiperblades are included, each group is located about 90° from each adjacentgroup, and the like. Accordingly, the dry wipe member 312 can be rotateda portion of a rotate about a rotational axis 519 (FIG. 4D) to move atleast some of the wiper blades 516 into a position for contacting theface of the print head 150, or into a position to not contact the faceof the print head 150.

In embodiments, the dry wipe member 312 is coupled to a motor 506 (FIGS.4B and 4D) that rotates the dry wipe member 312 about the rotationalaxis 519. The motor 506 can be, for example, a motor 506 coupled to abelt 507, which is in turn coupled to a pulley 508. The pulley 508 isaffixed to a shaft 509 extending from a center of the dry wipe member312. In various embodiments, the shaft 509 extends from the dry wipemember 312 in a direction along the rotational axis 519, and the shaft509 is in a fixed relationship with the dry wipe member 312 such thatrotation of the shaft 509 causes rotation of the dry wipe member 312 inthe same direction. In embodiments, the motor 506 can be coupled to thebelt 507 through a pulley (not shown). Accordingly, when the motor 506is activated, it drives the belt 507, which rotates the pulley 508 and,therefore, the shaft 509 of the dry wipe member 312. As the shaft 509 isrotated, the dry wipe member 312 rotates about the rotational axis 519,moving the wiper blades 516 in a circular motion around the rotationalaxis 519.

In the embodiment shown in FIG. 4B, each of the dry wipe member 312 andthe purge wipe member 313 is coupled to its own corresponding motor 506.However, it is contemplated that, in embodiments, a single motor 506 canbe used to drive more than one wipe member. For example, a single motor506 may be used to drive both the dry wipe member 312 and the purge wipemember 313. In such embodiments, the belt 507 may pass through atensioner after engaging the first wipe member and before engaging thesecond wipe member.

FIG. 4D further includes an access panel 510 coupled to the overflowvessel 318. The access panel 510 enables access to the motor 506 and thebelt 507, such as may be needed to adjust the tension of the belt. Forexample, if the dry wipe member 312 is moved in the −Z direction toreduce interference with the print head 150, the tension of the belt 507may be adjusted to remove slack resulting from the decreased Z distancebetween the pulley 508 and the motor 506.

Although the embodiments described herein are shown as including a beltand pulley drive, it is contemplated that, in embodiments, other typesof motors can be used. Suitable motors include, by way of example andnot limitation, chain-driven motors, worm gears, or gear-to-gear motors,one or more of which may be employed. In embodiments, the dry wipersection 306 can include a first type of motor while the purge wipersection 303 can include a second, different type of motor. Inembodiments, the dry wiper section 306 and the purge wiper section 303can include the same type of motor.

To enable the dry wipe member 312 to be rotated while being mountedwithin the cleaning station 110, in embodiments, the shaft 509 iscoupled to a bearing 512 that is received within a bearing housing 514.The bearing housing 514 is fixedly coupled to the cleaning station frame300.

In embodiments, the dry wipe reservoir 317 is positioned verticallybelow the dry wipe member 312 (e.g., in the −Z direction in the FIGS.)and maintains a volume of cleaning fluid through which the dry wipemember 312 is rotated for cleaning the dry wipe member 312. As shown inFIGS. 4B and 4C, the dry wipe reservoir 317 includes at least one inletport 520. For example, embodiments of the dry wipe reservoir 317 mayinclude a single inlet port, two inlet ports, or three or more inletports. In embodiments, the inlet port 520 extends through a wall of thedry wipe reservoir 317. The dry wipe reservoir 317 is coupled to acleaning fluid reservoir 816 (FIG. 9 ) through tubing or piping via theinlet port 520. Accordingly, cleaning fluid may be pumped from thecleaning fluid reservoir through the inlet port 520 and into the drywipe reservoir 317. In FIGS. 4B and 4C, the inlet port 520 is shown asextending through a bottom wall of the dry wipe reservoir 317, althoughit is contemplated that, in embodiments, the inlet port 520 may extendthrough one of the side walls of the dry wipe reservoir 317.

The dry wipe reservoir 317 may have any suitable cross-sectional shape,provided it is sized to contain a volume of cleaning fluid and enablethe wiper blades of the dry wipe member 312 to contact the cleaningfluid. For example, as shown in FIGS. 4B and 4C, the dry wipe reservoir317 includes side walls that extend from a bottom wall at an interiorangle of greater than 90°, while in FIGS. 6A and 6C, the dry wipereservoir 317 has a rounded cross-sectional shape. Other cross-sectionalshapes, including configurations having side walls that extend from thebottom wall at an interior angle of 90°, are contemplated and possible.

In addition to, or as an alternative to, the dry wipe reservoir 317, inembodiments, the dry wiper section 306 includes at least one wiper bladecleaning member 518. When included, the wiper blade cleaning member 518removes debris from the dry wipe member 312 as the dry wipe member 312is rotated past the wiper blade cleaning member 518 and contacts thewiper blade cleaning member 518. The wiper blade cleaning member 518 canbe, by way of example and not limitation, a brush (shown in FIGS. 4B,4C, 6B, and 6D), a wiper blade or set of wiper blades (shown in FIGS. 4Dand 6A) or the like. The wiper blade cleaning member 518 can bepositioned within the dry wipe reservoir 317, as shown in FIGS. 4B-4D, 5(wiper blade cleaning member 518 a in the purge wiper section 303 a),and 6A, or can be positioned within the cleaning station vessel 314independent of a dry wipe reservoir 317, as shown in FIG. 5 (the wiperblade cleaning member 518 b of the dry wiper section 306 a and the wiperblade cleaning member 518 c of the purge wiper section 303 a) and 6D.

In embodiments, such as shown in FIGS. 4B and 5 , a wiper blade cleaningmember 518 c may be positioned between the binder purge bin 302, 302 aand the purge wipe reservoir 315 to remove contaminants from the purgewipe member 313 a and direct the contaminants into the binder purge bin302, 302 a. In particular, the wiper blade cleaning member 518 c may bepositioned on a wall of the purge wipe reservoir 315 (as shown in FIG.4B), or the wiper blade cleaning member 518 c may be positioned on asurface of the cleaning station vessel 314 a (as shown in FIG. 5 ). Whenpresent between the binder purge bin 302, 302 a and the purge wipereservoir 315, the wiper blade cleaning member 518 c can reduce theamount of contaminants that are passed into the cleaning station vessel314, thereby reducing the amount of contaminants in the cleaning fluidthat is removed from the cleaning station vessel 314. This can, forexample, lead to a greater amount of recycling of the cleaning fluid,thereby reducing the need to provide fresh cleaning fluid to theadditive manufacturing apparatus. For example, the decreased amounts ofcontaminants can improve the recyclability of the cleaning fluid, andmay enable the cleaning fluid to be recirculated an increased number oftimes, as compared to embodiments that do not include the wiper bladecleaning member between the binder purge bin 302, 302 a and the purgewipe reservoir 315.

In some embodiments, the wiper blade cleaning member 518 can bestationary, although it is contemplated that the wiper blade cleaningmember 518 may, in embodiments, be configured to rotate or move inanother manner. For example, the wiper blade cleaning member 518 mayvibrate or move back and forth in the +/−Y or +/−Z directions, or at anangle (e.g., in the −Y/−X direction) to enhance the cleaning of the drywipe member 312. In embodiments, two wiper blade cleaning members 518can each be in the form of a rotating brush extending in a directionparallel to the direction of the dry wipe member 312, with one brushrotating in a clockwise direction and the other brush rotating in acounterclockwise direction, as shown in FIG. 6B. The two wiper bladecleaning members 518 can engage with one another at a location betweenthe two wiper blade cleaning members 518, and each wiper blade cleaningmember 518 can also engage with the dry wipe member 312. Accordingly, insuch embodiments, each wiper blade cleaning member 518 is configured toremove contaminants and/or cleaning fluid from both of the dry wipemember 312 and the other wiper blade cleaning member 518.

In embodiments, such as shown in FIG. 6C, instead of including aseparate wiper blade cleaning member 518, the dry wipe reservoir 317 maybe positioned to act as a wiper blade cleaning member. For example, thedry wipe reservoir 317 may be positioned at a distance adjacent to thedry wipe member 312 such that the wiper blades 516 of the dry wipemember 312 engage with a surface of the dry wipe reservoir 317 and thedry wipe reservoir 317 scrapes the wiper blades 516 as they rotatethrough the dry wipe reservoir 317. Alternatively or additionally, inembodiments in which the wet cleaning member 310 a is configured torotate, as in the embodiments shown in FIGS. 5 and 6G, the wiper blades516 of the wet cleaning member 310 a can engage with the wiper blades516 of the dry wipe member 312 to clean the wiper blades of the wetcleaning member 310 a and the dry wipe member 312. In embodiments, thewet cleaning member 310 a and the dry wipe member 312 rotate towards oneanother such that contaminants are directed down toward the cleaningstation vessel 314 instead of in a direction towards the print head (notshown).

In various embodiments, the wiper blade cleaning member 518, regardlessof its particular form, has a length extending in the lateral direction(e.g., +/−Y direction in the figures) that is substantially equal to alength of the dry wipe member 312 or to the wiper blades 516 of the drywipe member 312. In embodiments, multiple wiper blade cleaning members518 can be positioned adjacent to one another in the lateral directionalong an axis extending in the lateral direction such that the sumlength of the multiple wiper blade cleaning members is substantiallyequal to the length of the wiper blades 516 of the dry wipe member.Other configurations are contemplated, provided that substantially theentire length of the wiper blades 516 are contacted with the wipe bladecleaning member(s) 518. However, in embodiments, such as the embodimentshown in FIG. 6F, no wiper blade cleaning member is included, and thedry wipe member 312 is cleaned using a flow of cleaning fluid throughthe dry wipe reservoir 317.

In still other embodiments, a sprayer 522 can be included, as shown inFIG. 6E. For example, the sprayer 522 can spray cleaning fluid onto thedry wipe member 312 as it is rotated. In embodiments, an elongatedsprayer extending along the length of the dry wipe member 312 can bemounted to the dry wipe reservoir 317 or to the cleaning station vessel314, or a series of sprayers can be mounted to the dry wipe reservoir317 or to the cleaning station vessel 314. In such embodiments, the drywipe reservoir 317 may not receive a flow of cleaning fluid.Alternatively, when a sprayer 522 is included, the dry wipe reservoir317 may be omitted from the dry wiper section 306, as shown in FIG. 6E.

As yet another alternative, in embodiments, cleaning fluid can beapplied between the wiper blades 516 and the dry wipe member 312 can bevibrated, oscillated, or otherwise moved in one or more directions toagitate the cleaning fluid between the wiper blades 516. In embodiments,the dry wipe member 312 can be “rocked” or slightly rotated to cause thecleaning fluid to spill over one of the wiper blades 516 and flow overthe surface of the dry wipe member 312 to clean the wiper blades 516 andthe dry wipe member 312. The cleaning fluid can be applied, for example,using a sprayer or through a cleaning manifold extending through the drywipe member 312 (not shown), such as the cleaning manifold 414 describedabove and below with respect to the wet cleaning member 310.

It should be appreciated that, in embodiments, one or more features ofthe dry wiper section 306, and accordingly, the purge wiper section 303,described hereinabove can be combined with other features of the drywiper section 306, and accordingly, the purge wiper section 303.Moreover, it should be appreciated that the purge wiper section 303 canbe identical to or different from the dry wiper section 306, dependingon the particular embodiment.

Cleaning Station—Wet Cleaner Section

Various suitable embodiments are contemplated for the wet cleanersection 304. As shown in FIGS. 7A and 7B, the wet cleaner section 304comprises a wet cleaning member 310. The wet cleaning member 310comprises any suitable mechanism for passively applying cleaning fluidto a print head, for example, a brush, a squeegee, and the like. As usedherein, “passively applying” means the wet cleaning member 310, or thecleaning fluid provided by the wet cleaning member 310, contacts theprint head as it traverses the wet cleaner section 304. As describedhereinabove, in embodiments, the wet cleaning member 310 is a stationarycleaning member that provides a volume of cleaning fluid to the face ofthe print head as the print head traverses the wet cleaner section 304.However, in embodiments, such as the embodiments shown in FIGS. 5 and6G, the wet cleaning member 310 can rotate in a manner similar to thatdescribed above with respect to the dry wipe member 312.

Referring now to FIGS. 7A-7E, additional embodiments of the wet cleanersection 304 are schematically depicted. Specifically as shown in FIGS.7A-7E, a wet cleaning member 310 for applying cleaning fluid to theprint head 150 is depicted. The wet cleaning member 310 includes a wetcleaning body 401 having a top side 402 and a bottom side 404. Inembodiments, the wet cleaning member 310 includes at least one wiperblade 406 vertically extending from the top side 402 of the wet cleaningbody 401. In the embodiment shown in FIGS. 7A and 7B, the wet cleaningmember 310 includes a first wiper blade 406 a and a second wiper blade406 b (collectively, the wiper blades 406), spaced apart from oneanother. In the embodiment shown in FIG. 7C, the wet cleaning member 310includes a single wiper blade 406. Accordingly, any number wiper bladesmay be included in the wet cleaning member 310.

Although the wet cleaning member 310 is described in various embodimentsas including at least one wiper blade 406, in embodiments, the wetcleaning member 310 does not include wiper blades, as shown in FIG. 7E.

A fluid channel 408 extends horizontally from a first end 410 of the wetcleaning body 401 to a second end 412 of the wet cleaning body 401, asshown in FIGS. 7A-7C, and defines a recessed path within the wetcleaning body 401. The fluid channel 408 has an open top to allowcleaning fluid to flow out of the fluid channel 408. The rate of theflow of the cleaning fluid through the fluid channel 408 is controlledin embodiments, thereby enabling control of the height of a fluid wall418 created by the cleaning fluid, shown in FIG. 7E. In embodiments,such as the embodiment shown in FIGS. 7A and 7B, the fluid channel 408is positioned between the first wiper blade 406 a and the second wiperblade 406 b. Although the wiper blades 406 and the fluid channel 408 aredescribed herein as extending from a first end 410 to the second end 412of the wet cleaning body 401, in embodiments, the wet cleaning body 401has a length from the first end 410 to the second end 412 that isgreater than a length of the wiper blades 406 and/or the fluid channel408. For example, in embodiments, the wiper blades 406 and/or the fluidchannel 408 may be positioned within the wet cleaning body 401 with thewet cleaning body 401 extending about 1 mm, about 2 mm, about 5 mm, orabout 10 mm on each end. This additional length of the wet cleaning body401 can enable, for example, the wet cleaning body 401 to extend fromend to end of the cleaning station while the wiper blades 406 and/or thefluid channel 408 are sized to have substantially the same length as theprint head.

As shown in FIG. 7E, in embodiments in which the wet cleaning member 310does not include wiper blades 406, the flow of the cleaning fluidthrough the fluid channel 408 is controlled to provide a touchlesswiping system that uses the fluid wall 418 to wipe contaminants from theprint head without requiring the use of wiper blades. Moreover, it iscontemplated that, in some embodiments, the wet cleaning member 310 mayinclude wiper blades 406, but the wiper blades 406 do not contact theprint head during the cleaning. For example, the wiper blades 406, inembodiments, may serve to direct and control the cleaning fluid that isapplied to the print head.

In embodiments, each of the wiper blades 406 a has the same vertical(e.g., +/−Z) position as the other blades 406 b, as shown in FIG. 7A.Accordingly, all of the wiper blades 406 a, 406 b has the sameengagement distance with the print head 150 during wiping operations. Asis known in the art, the “engagement distance” refers to the amount bywhich the vertical position of the print head 150 and the verticalposition of an undeflected wiper blade 406 overlap. However, inembodiments, one or more wiper blades 406 a are positioned at a firstvertical position while one or more wiper blades 406 b are positioned ata second vertical position, as shown in FIG. 7F. In such embodiments, aleast one wiper blade 406 a has a different engagement distance than thewiper blades 406 b. For example, the wiper blades 406 may be positionedsuch that the engagement distance with the print head 150 increasesalong the path of the print head 150 during the wet cleaning process.

As shown in FIGS. 7A-7C, the wet cleaning member 310 further includes acleaning manifold 414 that extends below the fluid channel 408 withinthe wet cleaning body 401. The cleaning manifold 414 is in fluidcommunication with the fluid channel 408 through at least one fluid port407 to provide cleaning fluid from the cleaning manifold 414 to the topside 402 of the wet cleaning body 401, e.g., via the fluid channel 408.In the embodiment shown in FIG. 7B, twelve fluid ports 407 providecleaning fluid from the cleaning manifold 414 to the fluid channel 408.Each fluid port 407 may have a circular cross-section, a squarecross-section, or other cross-section suitable for fluid flow. However,in the embodiment shown in FIG. 7D, one fluid port 407 provides cleaningfluid from the cleaning manifold 414 to the fluid channel 408. The fluidport 407 in FIG. 7D extends from the first end 410 to the second end 412of the wet cleaning body 401 and has a substantially rectangularcross-section. Other shapes, sizes, and quantities of fluid ports arepossible and contemplated. In embodiments, such as the embodiment shownin FIG. 7B where the fluid channel 408 is positioned between first andsecond wiper blades 406, the fluid port 407 is also disposed between thefirst and second wiper blades 406.

In various embodiments, the cleaning fluid is provided to the cleaningmanifold 414 through a plurality of cleaning fluid inlets 416 that arefluidly coupled to a cleaning fluid reservoir or cleaning fluidmanagement system, described in greater detail below. The plurality ofcleaning fluid inlets 416 may be, for example, fluid conduits thatextend vertically upward through the bottom side 404 of the wet cleaningbody 401. However, in embodiments, the plurality of cleaning fluidinlets 416 additionally or alternatively extend from a side 403 of thewet cleaning body 401 adjacent to the top side 402 and the bottom side404 of the wet cleaning body 401. The plurality of cleaning fluid inlets416 are operable to receive the cleaning fluid and provide the cleaningfluid to the cleaning manifold 414. The cleaning fluid inlets 416 are influid communication with the fluid port 407 through the cleaningmanifold 414 such that cleaning fluid enters the cleaning manifold 414through the cleaning fluid inlets 416 and exits the cleaning manifold414 through the fluid port 407.

In some embodiments, a baffle (not shown) is positioned within the fluidchannel 408. The baffle can include one or more apertures or poresthrough which the cleaning fluid flows after entering the fluid channel408 from the fluid port(s) 407. When included, the baffle can facilitateequilibration of the flow of the cleaning fluid along the length of thefluid channel 408, such that a depth of the fluid along the length ofthe fluid channel 408 is substantially constant. Moreover, inembodiments, the baffle can reduce fluctuations in the height of a fluidwall created by the cleaning fluid flowing through the fluid port(s)407.

Accordingly, in embodiments, the cleaning fluid is fed through the wetcleaning member 310 continuously during operation of the additivemanufacturing apparatus. After the wet wipe member applies liquid to theprint head, the liquid then overflows back into the cleaning stationvessel 314. As described more below, within the cleaning station vessel314, there is a drain 320 (see FIG. 4C), which directs cleaning fluidinto a cleaning fluid reservoir 816 (see FIG. 9 ), and is then pumpedback into the wet cleaning member 310. The continuous cleanercirculation and recirculation is described more below. In embodiments,the rate of the flow of the cleaning fluid through the fluid channel 408is controlled in embodiments, thereby enabling control of the height ofa fluid wall 418 created by the cleaning fluid, shown in FIG. 7E. Forexample, the height of the fluid wall 418 may be increased to applycleaning fluid to the print head, and decreased when the print head isnot over the wet cleaner section 304, or when the cleaning fluid shouldnot be applied to the print head passing over the wet cleaner section304.

Accordingly, in embodiments, when the wet cleaning member 310 isactivated, cleaning fluid is supplied to the print head 150 to dissolvecontaminants. While the cleaning fluid may dissolve the contaminants insome cases, the contaminants may also be considered as mixed orsuspended within the cleaning fluid. The cleaning manifold 414 and thefluid channel 408 ensure that cleaning fluid can be directly applied tothe print head 150 during cleaning while compensating for any delay thatmay result from the use of pumps in the fluid management system, as willbe discussed in greater detail below. In particular, the cleaningmanifold 414 and the fluid channel 408 provide a local reservoir ofcleaning fluid that can be used even when the pumps are not activelyproviding cleaning fluid to the wet cleaning member 310.

In the embodiment depicted in FIG. 7A, the cleaning fluid does not flowto the top of the wiper blades 406. However, it is contemplated that inother embodiments, a pair of walls extends between the first wiper blade406 a and the second wiper blade 406 b from the top side 402 of the wetcleaning body 401 to a top of each of the first wiper blade 406 a andthe second wiper blade 406 b. The pair of walls thus extends the depthof the fluid channel 408 to the top of the wiper blades 406, enablingthe cleaning fluid to fill up to the top of the wiper blades 406. Suchembodiments may enable greater dissolution of contaminants on the printhead 150 and greater control of the cleaning fluid between the wiperblades 406.

In further embodiments, the dry wipe member 312 may be rotated such thatthe dry wipe member 312 the wiper blades that will contact the printhead are rotated out of the volume of the cleaning fluid with sufficienttime to allow the cleaning fluid to drain away from the dry wiper blades516. The dry wipe member 312 contacts the print head 150 as it is movedthrough the dry wiper section 306 to remove cleaning fluid, contaminantsand other debris from the print head 150 after the print head 150 iscleaned by the wet cleaning member 310.

Cleaning Station—Capping Section

As described with reference to FIGS. 4A-4C, in various embodiments, thecleaning station 110 includes a capping section 308 including a cover701 to create or maintain a non-curing environment around the print head150. As used herein, a “non-curing environment” means an environment inwhich the binder material does not cure within or on the surface of thenozzles of the print head 150. The non-curing environment may bemaintained, for example, by maintaining a particular humidity level,temperature, or the like, that prevents the binder material from curing.Various suitable embodiments are contemplated.

An example embodiment of a capping section 308 is shown in greaterdetail in FIG. 8 . In particular, the capping section 308 includes a cap710. In embodiments, the cap 710 may be sealed around the print head 150(not shown in FIG. 8 ) when the print head 150 is idle to prevent theevaporation of binder material from the nozzles of the print head 150,to maintain a humidity level around the print head 150, and/or tomaintain or create a non-curing environment around the print head 150.As shown in FIG. 8 , in embodiments, the cap 710 may include a volume ofcleaning fluid so as to create a humid, non-curing environment aroundthe nozzles of the print head 150, although in some embodiments, the cap710 may not include a volume of fluids.

In embodiments, the cap 710 is coupled to an optional actuator (notshown) that is operable to raise and lower the cap 710 within thecleaning fluid. The actuator may be a linear actuator, a rotaryactuator, a pneumatic actuator, an electric actuator, or any othersuitable type of actuator selected based on the particular embodiment.In some embodiments, the actuator may be coupled to a passive resistancemechanism (not shown), which biases the cap 710 toward a raised positionsuch that at least a portion of the cap 710 able to contact the printhead 150. The passive resistance mechanism may be, by way of example andnot limitation, a spring biased in an upward direction. Theincorporation of a passive resistance mechanism, though optional, servesas a fail-safe to ensure that, in the event of an actuator failure, thecap 710 is positioned for use to maintain the print head 150 in anon-curing environment. Additionally or alternatively, the incorporationof the passive resistance mechanism may enable energy savings byenabling power to the actuator to be reduced or turned off while theprint head 150 is idle without causing the cap 710 to be retracted.

In embodiments including an actuator, the actuator enables the height ofthe cap 710 to be adjusted relative to the print head 150. Accordingly,the cap 710 may be positioned to contact the print head 150 with fluidcontained within the cap 710, or the cap 710 may be positioned to capthe print head 150 such that the face of the print head 150 is notcontacted by the fluid. In embodiments in which the actuator is notincluded, the cap 710 may be positioned at a predetermined Z locationwith respect to the print head 150. The predetermined Z location may beselected to be a location that is within a specific distance from theface of the print head 150 to maintain a non-curing environment aroundthe print head 150.

In embodiments, the cap 710 may further include one or more gaskets orseals 712 to create a seal between the cap 710 and the print head 150when the cap 710 is in use. In some embodiments, the seals 712 may beinflatable seals that are inflated when the print head 150 is present inthe capping section 308. Accordingly, in such embodiments, the seals 712are deflated to enable the print head 150 to move into and out of thecapping section 308 without contacting the seals 712, and are inflatedwhen the print head 150 is in position within the capping section 308 toseal up against a surface of the print head 150 (e.g., the base plate ofthe print head 150) to maintain a non-curing environment. The creationof a seal may minimize or even eliminate evaporation of cleaning fluidin the cap 710, the binder material in the print head 150, or both.However, in other embodiments, the seals 712 may not be inflatable ormay not be inflated to contact the print head 150, and the cap 710 canprovide a vented, non-curing environment around the face of the printhead 150.

In embodiments, the cap 710 may include one or more ports 714 (e.g.,inlet and outlet ports) to enable cleaning fluid to be flowed throughthe cap 710 during use. Although depicted in FIG. 8 as being located ina bottom surface of the cap 710, in embodiments, one or more of theports 714 can be positioned in a side wall of the cap 710. Moreover, inembodiments, cleaning fluid can be supplied to the cap 710 through theports 714, and may exit the cap 710 by flowing over one or more sides(and, in embodiments, seals 712) of the cap 710. In embodiments, the cap710 is provided with cleaning fluid when the cap 710 is in use, but doesnot maintain a volume of cleaning fluid when the cap 710 is not in use.It is contemplated that, in some embodiments, the flow of the cleaningfluid into and/or out of the cap 710 can be regulated (e.g., through theuse of a throttling valve or the like), thereby enabling a level of thecleaning fluid within the cap 710 to be controlled and/or adjusted.

In the embodiment shown in FIG. 8 , the cap 710 further includes abaffle 708. Although optional, the baffle 708 distributes the flow ofthe cleaning fluid entering the cap 710, thereby enabling the cleaningfluid to be flowed into the cap 710 without contacting the print head150. For example, when the cleaning fluid is flowed into the cap 710 ata quick rate, it may have an increased fluid level directly above theports 714, which may contact the face of the print head at thoselocations. However, the baffle 708 can redistribute the cleaning fluidover the cap 710 such that the fluid level is substantially constantover the area of the cap 710, preventing any areas of increased fluidlevel, and preventing the cleaning fluid from contacting the print head150.

Cleaning Station—Motion of Components

As has been described herein, various components of the cleaning station110, including the dry wipe member 312, the purge wipe member 313 and,in some embodiments, the wet cleaning member 310 a, are configured torotate about an axis extending in the lateral (e.g., +/−Y) directionduring the cleaning of the print head 150. Although described hereinwith reference only to the rotational component of the movement, it iscontemplated that, in embodiments, the motion of the various componentsmay have motion in other directions in addition to the rotationaldirection. For example, the components may be moved in a rotational andvertical motion.

In general, the various components of the cleaning station 110 eachindependently moves between a contact position, in which the componentis positioned to engage with or clean the print head 150, and anon-contact position, in which the component is rotated to avoidengaging with the print head 150. For example, in embodiments, and withreference to FIG. 4A, the print head 150 enters the cleaning station 110from the right hand side of the figure, passing over the spit capturetray 307 first. In embodiments, as the print head 150 proceeds fromright to left, the capping section 308, the wet cleaning member 310, thedry wipe member 312, and the purge wipe member 313 are in thenon-contact position such that they do not contact or clean the printhead 150. For example, the dry wipe member 312 and the purge wipe member313 are rotated such that wiper blades 516 are not extending upwardsfrom the dry wipe member 312 or the purge wipe member 313, respectively,in a substantially vertical direction. The print head 150 arrives at thebinder purge bin 302, where backpressure is applied to the print head150 to discharge contaminants from the print head 150 into the binderpurge bin 302. In embodiments, during an additive manufacturing process,the print head 150 discharges contaminants into the binder purge bin 302while the recoat head 140 is moving in the −X direction (e.g., a forwarddirection) in FIG. 1 , supplying build material to a working surface ofthe build platform 120. The print head 150 then moves to the right,where the print head 150 is introduced to the purge wipe member 313. Thepurge wipe member 313 is in a contact position with one or more wiperblades 516 extending upwards vertically from the purge wipe member 313,as shown in FIGS. 4A-4C. Contaminants from the face of the print head150 are scraped by the purge wipe member 313, which directs thecontaminants into the binder purge bin 302 as the purge wipe member 313is rotated in the counterclockwise direction.

The print head 150 then moves again to the right, where the print head150 is introduced to the wet cleaning member 310. The wet cleaningmember 310 is in a contact position to apply cleaning fluid to the printhead 150. In embodiments, the “contact position” of the wet cleaningmember 310 is a configuration in which a flow of the cleaning fluid intothe fluid channel 408 is increased such that a fluid wall having aheight sufficient to contact the print head 150 is established.

Next, the print head 150 is introduced to the dry wipe member 312, whichhas moved to an contact position to wipe excess cleaning fluid from theprint head 150, as described herein. In embodiments, the purge wipemember 313 and/or the dry wipe member 312 are rotated such that thewiper blades that will contact the print head 150 are rotated out of thecleaning fluid (e.g., cleaning fluid in the purge wipe reservoir 315 orthe dry wipe reservoir 317) before the completion of the discharge ofthe contaminants from the print head 150 over the binder purge bin 302.The purge wipe member 313 and/or the dry wipe member 312 are rotatedsuch that the wiper blades that contacted the print head 150 are nolonger in a contact position (e.g., in an upright vertical position)after the print head 150 proceeds past them. In embodiments, during anadditive manufacturing process, the purge wiping, wet cleaning, and drywiping steps performed by the purge wipe member 313, the wet cleaningmember 310 and the dry wipe member 312, respectively, are performedwhile the recoat head 140 is moving in the +X direction (e.g., a reversedirection) from the build platform 120 toward a recoat home position148.

After being wiped, the print head 150 may be capped in the cappingsection 308, or it may proceed to the spit capture tray 307, where it isprepared for printing. For example, back pressure may be applied to theprint head 150 to equilibrate the print head 150 for printing. Inembodiments, the print head 150 then returns to the build platform 120to deposit binder material onto the powder layer, as described withrespect to FIG. 1 .

Alternative orders in the operations of the components of the cleaningstation 110 are contemplated. For example, in embodiments, the printhead 150 enters the cleaning station 110 from the right hand side of thefigure, passing over the spit capture tray 307 first. However, as theprint head 150 proceeds from right to left, the wet cleaning member 310,the dry wipe member 312, or the wet cleaning member 310 and the dry wipemember 312 are in the contact position such that they contact the printhead 150 along its path to the binder purge bin 302. In suchembodiments, this can be a pre-cleaning step to remove surfacecontaminants prior to the discharging of additional contaminants overthe binder purge bin 302.

Moreover, in some embodiments, the print head 150 may include featuresto control and/or direct cleaning fluid within the cleaning station 110,such as cleaning fluid that is wiped from the print head 150 by the drywipe member 312. For example, as the print head 150 proceeds through thecleaning station 110, cleaning fluid is applied to the face of the printhead by the wet cleaning member 310. The print head 150 then proceeds tothe dry wiper section 306, where the dry wipe member 312 contacts theface of the print head 150 to remove excess cleaning fluid from the faceof the print head 150. Engagement of the wiper blades 516 of the drywipe member 312 with the face of the print head 150 causes the wiperblades 516 to bend and, as the print head 150 passes the wiper blades516, the disengagement of the wiper blades 516 from the face of theprint head 150 allows the wiper blades 516 to spring back to theiroriginal position. However, this springing back can cause the cleaningfluid on the wiper blades 516 to be ejected from the wiper blades 516.If left unmanaged, the cleaning fluid can, for example, be ejectedupward into the print head 150. Accordingly, in embodiments, the printhead 150 includes a deflector plate 1348, as shown in FIGS. 10 and 11 .

The deflector plate 1348 is provided proximate a print home side wall1204 of a housing 1201 of the print head 150. The deflector plate 1348includes a body 1350 having a front end 1352, a rear end 1354, and apair of sides 1356, 1358. In embodiments, each side 1356, 1358 of thebody 1350 extends past the front end 1352 and includes a flange 1360extending perpendicular to the body 1350 of the deflector plate 1348. Inembodiments, each flange 1360 receives a fastener 1362 engaging aprinting head within the print head 150, such as the end walls 1208,1210 of the printing head to secure the deflector plate 1348 thereto.The fastener 1362 can be, as a non-limiting example, a screw, bolt,rivet, or the like.

In embodiments, the deflector plate 1348 is secured to a base plate 1202of the printing head 1154 such that the deflector plate 1348 moves inunison with the print heads 1156 as the print heads 1156 are operated toindex between end walls 1208, 1210 of the housing 1201. In thisembodiment, the deflector plate 1348 has a width at least as great as awidth of the base plate 1202 of the printing head to ensure that nocleaning solution accumulates on the base plate 1202. In embodiments,the deflector plate 1348 is fixed to the housing 1201 (e.g., to the endwalls 1208, 1210 of the housing 1201) so that the deflector plate 1348does not move in unison with the print heads 1156 as the print heads1156 index between the end walls 1208, 1210 of the housing 1201. Rather,the deflector plate 1348 is fixed. In this embodiment, the width of thedeflector plate 1348 is greater than the width of the base plate 1202 ofthe printing head and extends between opposite end walls 1208, 1210 ofthe housing 1201.

The deflector plate 1348 is dimensioned to provide a smooth transitionfrom the first surface 1344 of the base plate 1202 of the printing headto a bottom surface 1364 of the deflector plate 1348 to prevent cleaningfluid from flowing onto the printing head. Additionally, the rear end1354 and the sides 1356, 1358 of the deflector plate 1348 are curved toprevent the cleaning fluid from accumulating thereon and providing asmooth transition to the printing head. In embodiments, the rear end1354 extends past the base plate 1202 and/or the housing 1201 to preventcleaning fluid from accumulating on the print head 150. Morespecifically, the deflector plate 1348 operates as a “flick plate” dueto the curved rear end 1354 to deflect or flick cleaning fluid away fromthe print head 150 as the dry wipe member 312 moves across the printhead 150 and out of contact with the bottom surface 1364 of thedeflector plate 1348.

In embodiments, the deflector plate 1348 may be formed ofpolyetherimide, such as those commercially available under the trademarkULTEM™ (SABIC Innovative Plastics), which provides ease of fabricationand a high resistance to chemicals. In embodiments, the deflector plate1348 may be formed of a metal such as, for example, aluminum. When thedeflector plate 1348 is formed of metal, the deflector plate 1348 mayalso be coated with electroless nickel with co-deposited PTFE to providewear resistance and a low coefficient of friction. As shown in FIG. 11 ,a seal 1355 may be provided at an interface between the deflector plate1348 and the base plate 1202. Although only illustrated at the rear end1354 of the deflector plate 1348, the seal 1355 may extend along aninterior perimeter of the deflector plate 1348.

In embodiments, the deflector plate 1348 includes an outer layer 1366attached to an underside of the body 1350 of the deflector plate 1348.In embodiments, the outer layer 1366 has a surface roughness of equal toor less than 200 Ra (Roughness average). In embodiments, the outer layer1366 has a surface roughness of equal to or less than 125 Ra (Roughnessaverage). In embodiments, the outer layer 1366 has a surface roughnessof equal to or less than 75 Ra (Roughness average). The outer layer 1366of the deflector plate 1348 lies in the same plane as a first surface1344 of the base plate 1202 such that the deflector plate 1348 is flushwith the base plate 1202. The outer layer 1366 may be formed of anabsorbent material for absorbing cleaning fluid. The outer layer 1366may be secured to the surface of the body 1350 of the deflector plate1348 using any suitable attachment means such as, for example,fasteners, an adhesive, welded, or the like. In instances in which theouter layer 1366 is removable from the body 1350 of the deflector plate1348, the outer layer 1366 may be replaced when it no longer providesadequate absorption of the cleaning fluid. It should be appreciated thatthe entire deflector plate 1348 may be removed from the printing head1154 by removing the fasteners at the flanges 1360 so that the deflectorplate 1348 may be repaired or to replace the deflector plate 1348 with areplacement deflector plate. As described herein, the deflector plate1348 prevents defects from forming in the build platform 120 by cleaningfluid dropping onto the build platform 120 from the print head 150,thereby improving the quality of the object being built. Moreover, asdescribed hereinabove, the deflector plate 1348 provides an interfacethat maintains contact between the print head 150 and the wiper blades516 of the dry wipe member 312 such that the wiper blades 516 aredisengaged from the print head 150 at a time and location with respectto the print head 150 such that cleaning fluid ejected from the wiperblades 516 is not deposited on or within the print head 150.

Having described various sections of a cleaning station 110, a fluidmanagement system suitable for providing cleaning fluid to the cleaningstation 110 and binder material to the print head 150 will now bedescribed in detail.

Fluid Management System

Referring now to FIG. 9 in conjunction with FIG. 1 , a fluid managementsystem 900 includes a binder material pathway for providing bindermaterial 500 to a print head 150 and for recycling binder material 500not deposited on build material 400 positioned on the build platform 120and a cleaning fluid pathway for providing cleaning fluid to thecleaning station 110 for cleaning the print head 150 between depositingoperations and recycling and reconditioning cleaning fluid to minimizethe amount of cleaning fluid that is wasted.

In general, the binder material pathway includes a binder reservoir 802that is in fluid communication with the print head 150 and the binderpurge bin 302. The binder purge bin 302 may include an active drain 806,which allows binder flow from the binder purge bin 302 into the binderreservoir 802. Further, as shown, the binder purge bin 302 may includean overflow drain 812 disposed on the sidewall of the binder purge bin302, which releases binder from the binder purge bin 302 if a level ofbinder in the binder purge bin 302 exceeds a desired binder fluid level.In some embodiments, level sensors may be included to ensure binderfluid level is properly monitored and maintained.

Referring again to FIG. 9 , the binder material pathway enablesrecirculation of the binder material to reduce or even eliminateclogging of the binder material in the nozzles of the print head 150.

The binder material is provided from the binder reservoir 802 to an inkdelivery system 804 which in turn delivers the binder material to theprint head 150. The ink delivery system 804 enables the separation ofstorage of the binder material from the print head 150 and allows forthe binder material to be replaced or refilled while the additivemanufacturing apparatus 100 is actively printing. The print head 150discharges the binder material through nozzles into, for example, thebuild area and the binder purge bin 302.

Binder material discharged into the binder purge bin 302 passes throughan active drain 806. In the embodiment depicted in FIG. 9 , the activedrain 806 is located at or near a bottom of the binder purge bin 302, toenable the binder material to be recirculated without requiring theaccumulation of the binder material in the binder purge bin 302. Inembodiments, the active drain 806 is in fluid communication with a pump808 that actively moves the binder material from the active drain 806through a filter 810 and back to the binder reservoir 802. The filter810 may remove contaminants or large particles, such as polymers thathave agglomerated as a result of partial evaporation of the bindermaterial and build material particles, to ensure that the bindermaterial that is returned to the binder reservoir 802 is suitable forrecirculation through the binder material pathway.

As shown in FIG. 9 , the binder purge bin 302 further includes anoverflow drain 812 located through a sidewall of the binder purge bin302. In embodiments, the overflow drain 812 is located within the tophalf of the height of the sidewall of the binder purge bin 302. Theoverflow drain 812 is in fluid communication with a waste reservoir 814.In embodiments, the overflow drain 812 may be a passive drain.Accordingly, in the event that the active drain 806 becomes clogged orbinder material otherwise accumulates to a level greater than or equalto the position of the overflow drain 812, the binder material can bedrained from the binder purge bin 302 and removed from the bindermaterial pathway via the waste reservoir 814. In the event of a clog inthe active drain 806, the binder material removed from the binder purgebin 302 is directed from the overflow drain 812 to the waste reservoir814 so as to minimize the amount of contaminants recirculated throughthe system, although in some embodiments, it is contemplated that theoverflow drain 812 may be in fluid communication with the binderreservoir 802, such as through the filter 810.

In embodiments, the overflow drain 812 is coupled to the binderreservoir 802 and the waste reservoir 814 through a valve 815, althoughother pathways are contemplated. Valve 815 can be, for example, a pinchvalve, a three-way valve, or a four-way valve, although other types ofvalves are contemplated. It is further contemplated that the overflowdrain 812 can be fluidly coupled to another part of the main circulationpath instead of being fluidly coupled to the binder reservoir 802.

In embodiments including the valve 815, binder material overflowing fromthe binder purge bin 302 flows through the overflow drain 812. Bindermaterial flowing through the overflow drain 812 is evaluated and, ifverified that the binder material flowing through the overflow drain 812is still usable, the binder material is returned to the binder reservoir802. If, however, the binder material in the overflow vessel 318 is notstill suitable for use (e.g., it contains too many contaminants or doesnot otherwise meet specifications for use), the binder material is sentto the waste reservoir 814. In embodiments including the valve 815, thevalve 815 can be controlled by a computing device, such as controlsystem 200 that is configured to verify the suitability of the bindermaterial for use and send a signal to the valve 815 to direct the bindermaterial to the binder reservoir 802 or the waste reservoir 814.

Turning now to the cleaning fluid pathway depicted in FIG. 9 , thecleaning fluid pathway generally includes a cleaning fluid reservoir 816that is in fluid communication with the purge wipe reservoir 315, thewet cleaning member 310, the dry wipe reservoir 317, the spit capturetray 307, and the capping section 308 of the cleaning station 110. Thecleaning fluid pathway enables cleaning fluid to be applied to the printhead 150 to fluidize particles deposited on the print head 150, such asbuild material particles and binder material particles, while furtherenabling the cleaning fluid to be recirculated and reconditioned toreduce the amount of cleaning fluid that is wasted.

In embodiments, the cleaning fluid is provided from the cleaning fluidreservoir 816 to a pump 820, which in turn delivers the cleaning fluidto the purge wipe reservoir 315, the wet cleaning member 310, the drywipe reservoir 317, the cap 710, and the spit capture tray 307 throughcorresponding fluid inlets (not shown in FIG. 9 ). In particular, thepump 820 delivers the cleaning fluid to the purge wipe reservoir 315 andthe dry wipe reservoir through corresponding inlet ports 520, to the wetcleaning member 310 through the cleaning fluid inlets 416, to the cap710 through the ports 714 (FIG. 8 ), and to the spit capture tray 307through fluid inlets 309. Although in the embodiment shown in FIG. 9 , asingle pump 820 is shown as pumping the cleaning fluid to the purge wipereservoir 315, the wet cleaning member 310, the dry wipe reservoir 317,the cap 710, and the spit capture tray 307, it is contemplated that inembodiments, additional pumps may be used to pump the cleaning fluid tothe various components. For example, in embodiments a first pump may beused to pump the cleaning fluid to the wet cleaning member 310 and asecond pump may be used to pump the cleaning fluid to the purge wipereservoir 315, the dry wipe reservoir 317, the cap 710, and the spitcapture tray 307. As another example, a first pump may be used to pumpthe cleaning fluid to the wet cleaning member 310, a second pump may beused to pump the cleaning fluid to the purge wipe reservoir 315, a thirdpump may be used to pump the cleaning fluid to the dry wipe reservoir317, a fourth pump may be used to pump the cleaning fluid to the spitcapture tray 307, and a fifth pump may be used to pump the cleaningfluid to the cap 710. Other configurations are possible andcontemplated.

As the cleaning fluid is pumped into each of the purge wipe reservoir315, the wet cleaning member 310, the dry wipe reservoir 317, the cap710, and the spit capture tray 307, the volume of the cleaning fluidaccumulates to a fluid level within the corresponding cleaning stationcomponent. The volume of cleaning fluid is used to supply cleaning fluidto the wet cleaning member 310, the spit capture tray 307, and the cap710 or sponge 702, as described hereinabove, and to supply cleaningfluid to the dry wipe reservoir 317 and purge wipe reservoir 315 forcleaning the dry wipe member 312 and purge wipe member 313,respectively, between uses. In embodiments, the cleaning fluid inlets(e.g., inlet ports 520, cleaning fluid inlets 416, and fluid inlets 309)can be left open to constantly feed cleaning fluid to the dry wipereservoir 317, the wet cleaning member 310, the purge wipe reservoir315, and the spit capture tray 307 when the machine is in operation,each of which is then overflowed into the cleaning station vessel 314.

The cleaning station vessel 314 includes a main cleaning vessel drain320 that is in fluid communication with the cleaning fluid reservoir 816through a filter 818. The main cleaning vessel drain 320, which is alsodepicted in FIGS. 4C and 4D, is positioned within the cleaning stationvessel 314 enable continual removal of cleaning fluid from the cleaningstation vessel 314. Accordingly, when the volume of cleaning fluidoverflows from the dry wipe reservoir 317, the wet cleaning member 310,the purge wipe reservoir 315, and/or the spit capture tray 307, thecleaning fluid is caught by the cleaning station vessel 314 and isdrained from the cleaning station vessel 314 via the main cleaningvessel drain 320 and returned to the cleaning fluid reservoir 816. Inone or more embodiments, the main cleaning vessel drain 320 may be anactive drain coupled to a pump, or may be a passive drain, which allowsthe cleaning fluid to pass out of the cleaning station vessel 314without the use of a pump or other active mechanism.

In the embodiment shown in FIG. 9 , the cleaning station vessel 314further includes an overflow drain 323 that is in fluid communicationwith the overflow vessel 318. The overflow drain 323 can be a passivedrain that is opened allow at least a portion of the cleaning fluid thatis in the cleaning station vessel 314 to be flow from the cleaningstation vessel 314 to the overflow vessel 318, such as in the event thatthe main cleaning vessel drain 320 becomes clogged.

The overflow vessel 318 further includes at least one overflow vesseldrain 322 that is in fluid communication with the waste reservoir 814.In one or more embodiments, the overflow vessel drain 322 may be anactive drain coupled to a pump (not shown), or may be a passive drain,which allows the cleaning fluid to pass out of the overflow vessel 318without the use of a pump or other active mechanism. In embodiments, theoverflow vessel 318 is coupled to the filter 818 and the cleaning fluidreservoir 816 and the waste reservoir 814 through a valve 813, althoughother pathways are contemplated. Valve 813 can be, for example, a pinchvalve, a three-way valve, or a four-way valve, although other types ofvalves are contemplated. It is further contemplated that the overflowvessel drain 322 can be fluidly coupled to another part of the maincirculation path instead of being fluidly coupled to the filter 818 andthe cleaning fluid reservoir 816.

In embodiments including the valve 813, cleaning fluid flowing from theoverflow vessel 318 flows through the overflow vessel drain 322.Cleaning fluid in the overflow vessel 318 is evaluated and, if verifiedthat the cleaning fluid in the overflow vessel 318 is still usable, thecleaning fluid is returned to the cleaning fluid reservoir 816. If,however, the cleaning fluid in the overflow vessel 318 is not stillsuitable for use (e.g., it contains too many contaminants or does nototherwise meet specifications for use), the cleaning fluid is sent tothe waste reservoir 814. In embodiments including the valve 813, thevalve 813 can be controlled by a computing device, such as controlsystem 200 that is configured to verify the suitability of the cleaningfluid for use and send a signal to the valve 813 to direct the cleaningfluid to the cleaning fluid reservoir 816 or the waste reservoir 814.

In various embodiments, one or more additional components (not shown inFIG. 9 ) may be included in the fluid management system 900 as part ofone or both of the binder material pathway or the cleaning fluidpathway. For example, level sensors, flow sensors, cameras, heaters,cooling units, temperature sensors, pumps, filters, valves, or the likemay be included in the fluid management pathways to enable monitoring,control, and adjustment of the fluids in the pathways. Such additionalcomponents may be included in any of a variety of locations within thefluid management system 900 and may be communicatively coupled to thecontrol system 200. For example, in embodiments, the cleaning fluid pathincludes a heater to heat the cleaning fluid prior to it entering thecleaning station vessel 314. When included, the heater may be positionedat any of a number of points along the cleaning fluid path, such asbetween the pump 820 and the cleaning station vessel 314, or within thecleaning fluid reservoir 816.

As another example, in embodiments a three-way or four-way valve may bepositioned within the main cleaning vessel drain 320 and the cleaningfluid reservoir 816 to redirect a predetermined amount of the cleaningfluid to the waste reservoir 814. Accordingly, in embodiments, thethree-way or four-way valve may replace or replicate the functionalityof the main cleaning vessel drain 320. Moreover, it is contemplated thatone or more on/off valves (e.g., pinch valves) may be used in place ofor in addition to the three- or four-way valves described herein.

In embodiments, one or more of the pumps described herein, including butnot limited to pump 808 and pump 820, are capable of moving ferrousmetals as well as other types of metals. Moreover, in embodiments, oneor more of the pumps described herein may include a tunable flow rate,such as through flow regulators, which enable the flow rate to be tuned,such as to enable cleaning fluid to be provided to the wet wipe memberat a first flow rate and to the inlet of the cleaning station vessel ata second flow rate.

Having described a fluid management system 900 for use in providingbinder material and cleaning fluid to various components of the additivemanufacturing apparatus 100, and specifically, the cleaning station 110,the binder material and cleaning fluid will now be described in detail.

Control System

Referring now to FIG. 3 , FIG. 3 schematically depicts a control system200 for controlling the components of the cleaning station and thebinder and the cleaning fluid pathways. The control system 200 iscommunicatively coupled to at least the print head, the pump 808 and thepump 820. In embodiments, the control system 200 may additionally becommunicatively coupled to at least one additional sensor, such as asensor for monitoring one or more physical properties of the cleaningfluid, as described in greater detail above, the motors 506 coupled tothe dry wipe member 312 and the purge wipe member 313, and the actuator706 coupled to the sponge support 704 or cap 710. In the embodimentsdescribed herein, the control system 200 comprises a processor 202communicatively coupled to a memory 204. The processor 202 may includeany processing component(s), such as a central processing unit or thelike, configured to receive and execute computer readable and executableinstructions stored in, for example, the memory 204. In the embodimentsdescribed herein, the processor 202 of the control system 200 isconfigured to provide control signals to (and thereby actuate) the printhead 150, the pump 808, and the pump 820.

In embodiments, the control system 200 may be configured to receivesignals from one or more sensors of the fluid management system and,based on these signals, actuate one or more of the print head 150, thepump 808, the pump 820, or other valves, pumps, and drains that may beincluded in the fluid management system. In some embodiments, thecontrol system 200 may be configured to receive signals from one or moreadditional sensors in the additive manufacturing apparatus 100 and,based on these signals, actuate one or more of the motors 506 coupled tothe dry wipe member 312 and the purge wipe member 313 to rotate thecomponents of the cleaning station 110 for use.

In various embodiments, the control system 200 is configured to receivesignals from and send signals to one or more components describedherein. Accordingly, the control system 200, in embodiments, can enableone or more of the functions described herein, including, withoutlimitation, movement of any or all of the components of the cleaningstation (e.g., the wet wipe member, the dry wipe member, the purge wipemember, and the capping section), adjustment of one more componentsdescribed herein, monitoring the status of binder material and/orcleaning fluid described herein, monitoring performance of the additivemanufacturing apparatus or any component thereof, measurements ofvarious components, opening and closing of ports and valves, and thelike. In embodiments, the control system 200 is configured to controlmotion of the recoat head, the print head, and other components of theadditive manufacturing device described herein.

Moreover, it is contemplated that, although control system 200 is shownin FIG. 3 as being a single computing device, the control system 200 maybe a distributed system that includes multiple computing devicesinterconnected to perform the functions herein.

In the embodiments described herein, the computer readable andexecutable instructions for controlling the additive manufacturingapparatus 100, and particularly, the cleaning station 110 and the fluidmanagement system, are stored in the memory 204 of the control system200. The memory 204 is a non-transitory computer readable memory. Thememory 204 may be configured as, for example and without limitation,volatile and/or nonvolatile memory and, as such, may include randomaccess memory (including SRAM, DRAM, and/or other types of random accessmemory), flash memory, registers, compact discs (CD), digital versatilediscs (DVD), and/or other types of storage components.

Further aspects of the invention are provided by the subject matter ofthe following clauses:

1. A cleaning station comprising: a first wipe member rotatable about afirst rotational axis comprising one or more wiper blades; a first wipereservoir containing a volume of cleaning fluid therein, the first wipereservoir located adjacent to the first wipe member such that as thefirst wipe member is rotated about the first rotational axis, the one ormore wiper blades are rotated into and out of the volume of cleaningfluid in the first wipe reservoir; a second wipe member rotatable abouta second rotational axis parallel to the first rotational axis, thesecond wipe member comprising one or more wiper blades; a second wipereservoir containing a volume of cleaning fluid therein, the second wipereservoir located adjacent to the second wipe member such that as thesecond wipe member is rotated about the second rotational axis, the oneor more wiper blades are rotated into and out of the volume of cleaningfluid in the second wipe reservoir; and a wet cleaning member comprisinga fluid channel containing a volume of cleaning fluid therein, whereinthe wet cleaning member is positioned between the first wipe member andthe second wipe member along a longitudinal axis extending substantiallyperpendicular to the first rotatable axis and the second rotatable axis.

2. A cleaning station comprising the cleaning station of any precedingclause, further comprising a spit capture tray containing a volume ofcleaning fluid therein.

3. A cleaning station comprising the cleaning station of any precedingclause, wherein the spit capture tray comprises a first side wall and asecond side wall, and wherein a height of the first side wall is lessthan an height of the second side wall.

4. A cleaning station comprising the cleaning station of any precedingclause, further comprising a cover operable to create or maintain anon-curing environment around a print head.

5. A cleaning station comprising the cleaning station of any precedingclause further comprising: a cleaning station vessel positioned belowthe first wipe member, the second wipe member, and the wet cleaningmember to receive cleaning fluid therefrom.

6. A cleaning station comprising the cleaning station of any precedingclause, wherein the cleaning station vessel comprises a bottom surfacethat is angled with respect to a horizontal plane and with respect to avertical plane.

7. A cleaning station comprising the cleaning station of any precedingclause, the cleaning station vessel comprising a main cleaning vesseldrain positioned at a lowest vertical point of the cleaning stationvessel.

8. A cleaning station comprising the cleaning station of any precedingclause, further comprising an overflow vessel at least partiallysurrounding the cleaning station vessel.

9. A cleaning station comprising the cleaning station of any precedingclause, wherein at least one of the first wipe reservoir and the secondwipe reservoir comprise a brush or a wiper blade positioned therein tomechanically clean the corresponding first or second wipe member.

10. A cleaning station comprising the cleaning station of any precedingclause, further comprising: a first motor coupled to the first wipemember to cause the first wipe member to rotate about the firstrotational axis; and a second motor coupled to the second wipe member tocause the second wipe member to rotate about the second rotational axis.

11. A cleaning station comprising the cleaning station of any precedingclause, further comprising: a motor coupled to the first wipe member andthe second wipe member to cause the first wipe member to rotate aboutthe first rotational axis and to cause the second wipe member to rotateabout the second rotational axis.

12. A cleaning station comprising the cleaning station of any precedingclause, wherein the wet cleaning member is stationary with respect tothe first wipe member and the second wipe member.

13. A cleaning station comprising the cleaning station of any precedingclause, further comprising a purge bin, wherein the first wipe memberrotates in a direction effective to direct material from the one or morewiper blades of the first wipe member into the purge bin.

14. A cleaning station comprising the cleaning station of any precedingclause, further comprising a wiper blade cleaning member between thepurge bin and the first wipe reservoir.

15. A method of cleaning a print head comprising: rotating a first wipemember and a second wipe member into a contact position in which one ormore wiper blades extends upwards vertically from each of the first wipemember and the second wipe member; flowing cleaning fluid to a cleaningmember positioned between the first wipe member and the second wipemember; passing the print head over the first wipe member, therebyenabling the first wipe member to remove contaminants from the printhead; passing the print head over the cleaning member and the secondwipe member, thereby enabling the second wipe member to remove cleaningfluid from the print head; and rotating the first wipe member and thesecond wipe member into non-contact position in which one or more wiperblades are not extending from the first wipe member or the second wipemember in a substantially vertical direction.

16. A method comprising the method of any preceding clause, furthercomprising: applying backpressure to the print head prior to passing theprint head over the first wipe member.

17. A method comprising the method of any preceding clause, furthercomprising: passing the print head over a spit capture tray adjacent tothe second cleaning member; and applying backpressure to the print headduring passing of the print head over spit capture tray, therebyequilibrating the print head for printing.

18. A method comprising the method of any preceding clause, furthercomprising: providing a flow of cleaning fluid to the spit capture tray.

19. A method comprising the method of any preceding clause, furthercomprising: rotating the first wipe member and the second wipe member tocontact the one or more wiper blades with cleaning fluid contained in awipe reservoir positioned below the first wipe member and the secondwipe member.

20. A method comprising the method of any preceding clause, furthercomprising: collecting cleaning fluid from the wipe reservoir and thecleaning member in a cleaning station vessel.

21. A method comprising the method of any preceding clause, furthercomprising: continuously removing the cleaning fluid from the cleaningstation vessel.

22. A method comprising the method of any preceding clause, wherein theprint head comprises a deflector plate that maintains contact betweenthe print head 150 and the one or more wiper blades of the second wipemember.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the embodiments describedherein without departing from the spirit and scope of the claimedsubject matter. Thus it is intended that the specification cover themodifications and variations of the various embodiments described hereinprovided such modification and variations come within the scope of theappended claims and their equivalents.

The invention claimed is:
 1. A cleaning station, comprising: a firstwipe member rotatable about a first rotational axis comprising one ormore wiper blades; a first wipe reservoir containing a volume ofcleaning fluid therein, the first wipe reservoir located adjacent to thefirst wipe member such that as the first wipe member is rotated aboutthe first rotational axis, the one or more wiper blades are rotated intoand out of the volume of cleaning fluid in the first wipe reservoir; asecond wipe member rotatable about a second rotational axis parallel tothe first rotational axis, the second wipe member comprising one or morewiper blades; a second wipe reservoir containing a volume of cleaningfluid therein, the second wipe reservoir located adjacent to the secondwipe member such that as the second wipe member is rotated about thesecond rotational axis, the one or more wiper blades are rotated intoand out of the volume of cleaning fluid in the second wipe reservoir;and a wet cleaning member comprising a fluid channel containing a volumeof cleaning fluid therein, wherein the wet cleaning member is positionedbetween the first wipe member and the second wipe member along alongitudinal axis extending substantially perpendicular to the firstrotatable axis and the second rotatable axis.
 2. The cleaning station ofclaim 1, further comprising a spit capture tray containing a volume ofcleaning fluid therein.
 3. The cleaning station of claim 2, wherein thespit capture tray comprises a first side wall and a second side wall,and wherein a height of the first side wall is less than an height ofthe second side wall.
 4. The cleaning station of claim 1, furthercomprising a cover operable to create or maintain a non-curingenvironment around a print head.
 5. The cleaning station of claim 1,further comprising: a cleaning station vessel positioned below the firstwipe member, the second wipe member, and the wet cleaning member toreceive cleaning fluid therefrom.
 6. The cleaning station of claim 5,wherein the cleaning station vessel comprises a bottom surface that isangled with respect to a horizontal plane and with respect to a verticalplane and a main cleaning vessel drain positioned at a lowest verticalpoint of the cleaning station vessel.
 7. The cleaning station of claim5, further comprising an overflow vessel at least partially surroundingthe cleaning station vessel.
 8. The cleaning station of claim 1, whereinat least one of the first wipe reservoir and the second wipe reservoircomprise a brush or a wiper blade positioned therein to mechanicallyclean the corresponding first or second wipe member.
 9. The cleaningstation of claim 1, further comprising: a first motor coupled to thefirst wipe member to cause the first wipe member to rotate about thefirst rotational axis; and a second motor coupled to the second wipemember to cause the second wipe member to rotate about the secondrotational axis.
 10. The cleaning station of claim 1, furthercomprising: a motor coupled to the first wipe member and the second wipemember to cause the first wipe member to rotate about the firstrotational axis and to cause the second wipe member to rotate about thesecond rotational axis.
 11. The cleaning station of claim 1, wherein thewet cleaning member is stationary with respect to the first wipe memberand the second wipe member.
 12. The cleaning station of claim 1, furthercomprising a purge bin, wherein the first wipe member rotates in adirection effective to direct material from the one or more wiper bladesof the first wipe member into the purge bin.
 13. The cleaning station ofclaim 12, further comprising a wiper blade cleaning member disposedbetween the purge bin and the first wipe reservoir.